prompt_front: Answer the question based on the given passages. Only give me the answer and do not output any other words.

Question: The large subunit and small subunit that use two types of RNA are major components that make up what?

The following are given passages.
Context 1: Passage 1:
Short interspersed nuclear elements (SINEs)
Short interspersed nuclear elements (SINEs) are non-autonomous, non-coding transposable elements (TEs) that are about 100 to 700 base pairs in length  They are a class of retrotransposons, DNA elements that amplify themselves throughout eukaryotic genomes, often through RNA intermediates  SINEs compose about 13% of the mammalian genome The internal regions of SINEs originate from tRNA and remain highly conserved, suggesting positive pressure to preserve structure and function of SINEs   While SINEs are present in many species of vertebrates and invertebrates, SINEs are often lineage specific, making them useful markers of divergent evolution between species  Copy number variation and mutations in the SINE sequence make it possible to construct phylogenies based on differences in SINEs between species  SINEs are also implicated in certain types of genetic disease in humans and other eukaryotes 
In essence, short interspersed nuclear elements are genetic parasites which have evolved very early in the history of eukaryotes to utilize protein machinery within the organism as well as to co-opt the machinery from similarly parasitic genomic elements  The simplicity of these elements make them remarkably successful at persisting and amplifying (through retrotransposition)  within the genomes of eukaryotes  These "parasites" which have become ubiquitous in genomes can be very deleterious to organisms as discussed below  However, eukaryotes have been able to integrate short-interspersed nuclear elements into different signaling, metabolic and regulatory pathways and SINEs have become a great source of genetic variability  They seem to play a particularly important role in the regulation of gene expression and the creation of RNA genes  This regulation extends to chromatin re-organization and the regulation of genomic architecture  The different lineages, mutations, and activities among eukaryotes make short-interspersed nuclear elements a useful tool in phylogenetic analysis 

Classification and structure
SINEs are classified as non-LTR retrotransposons because they do not contain long terminal repeats (LTRs)  There are three types of SINEs common to vertebrates and invertebrates: CORE-SINEs, V-SINEs, and AmnSINEs  SINEs have 50-500 base pair internal regions which contain a tRNA-derived segment with A and B boxes that serve as an internal promoter for RNA polymerase III 

Internal structure
SINEs are characterized by their different modules, which are essentially a sectioning of their sequence  SINEs can, but do not necessarily have to possess a head, a body, and a tail  The head, is at the 5' end of short-interspersed nuclear elements and is an evolutionarily derived from an RNA synthesized by RNA Polymerase III such as ribosomal RNAs and tRNAs; the 5' head is indicative of which endogenous element that SINE was derived from and was able to parasitically utilize its transcriptional machinery  For example, the 5' of the Alu sine is derived from 7SL RNA, a sequence transcribed by RNA Polymerase III which codes for the RNA element of SRP, an abundant ribonucleoprotein  The body of SINEs possess an unknown origin but often share much homology with a corresponding LINE which thus allows SINEs to parasitically co-opt endonucleases coded by LINEs (which recognize certain sequence motifs)  Lastly, the 3′ tail of SINEs is composed of short simple repeats of varying lengths; these simple repeats are sites where two (or more) short-interspersed nuclear elements can combine to form a dimeric SINE  Short-interspersed nuclear elements which only possess a head and tail are called simple SINEs whereas short-interspersed nuclear elements which also possess a body or are a combination of two or more SINEs are complex SINEs 

Transcription
Short-interspersed nuclear elements are transcribed by RNA polymerase III which is known to transcribe ribosomal RNA and tRNA, two types of RNA vital to ribosomal assembly and mRNA translation  SINEs, like tRNAs and many small-nuclear RNAs possess an internal promoter and thus are transcribed differently than most protein-coding genes   In other words, short-interspersed nuclear elements have their key promoter elements within the transcribed region itself  Though transcribed by RNA polymerase III, SINEs and other genes possessing internal promoters, recruit different transcriptional machinery and factors than genes possessing upstream promoters 

Effects on gene expression
Changes in chromosome structure influence gene expression primarily by affecting the accessibility of genes to transcriptional machinery  The chromosome has a very complex and hierarchical system of organizing the genome  This system of organization, which includes histones, methyl groups, acetyl groups, and a variety of proteins and RNAs allows different domains within a chromosome to be accessible to polymerases, transcription factors, and other associated proteins to different degrees   Furthermore, the shape and density of certain areas of a chromosome can affect the shape and density of neighboring (or even distant regions) on the chromosome through interaction facilitated by different proteins and elements  Non-coding RNAs  such as short-interspersed nuclear elements, which have been known to associate with and contribute to chromatin structure, can thus play huge role in regulating gene expression   Short-interspersed-nuclear-elements similarly can be involved in gene regulation by modifying genomic architecture 
In fact Usmanova et al  2008 suggested that short-interspersed nuclear elements can serve as direct signals in chromatin rearrangement and structure   The paper examined the global distribution of SINEs in mouse and human chromosomes and determined that this distribution was very similar to genomic distributions of genes and CpG motifs  The distribution of SINEs to genes was significantly more similar than that of other non-coding genetic elements and even differed significantly from the distribution of long-interspersed nuclear elements  This suggested that the SINE distribution was not a mere accident caused by LINE-mediated retrotransposition but rather that SINEs possessed a role in gene-regulation  Furthermore, SINEs frequently contain motifs for YY1 polycomb proteins  YY1 is a zinc-finger protein that acts as a transcriptional repressor for a wide-variety of genes essential for development and signaling   Polycomb protein YY1 is believed to mediate the activity of histone deacetylases and histone acetyltransferases to facilitate chromatin re-organization; this is often to facilitate the formation of heterochromatin (gene-silencing state)  Thus, the analysis suggests that short-interspersed nuclear elements can function as a ‘signal-booster' in the polycomb-dependent silencing of gene-sets through chromatin re-organization   In essence, it is the cumulative effect of many types of interactions that leads to the difference between euchromatin, which is not tightly packed and generally more accessible to transcriptional machinery, and heterochromatin, which is tightly packed and generally not accessible to transcriptional machinery; SINEs seem to play an evolutionary role in this process 
In addition to directly affecting chromatin structure, there are a number of ways in which SINEs can potentially regulate gene expression  For example, long non-coding RNA can directly interact with transcriptional repressors and activators, attenuating or modifying their function   This type of regulation can occur in different ways: the RNA transcript can directly bind to the transcription factor as a co-regulator; also, the RNA can regulate and modify the ability of co-regulators to associate with the transcription factor   For example, Evf-2, a certain long non-coding RNA, has been known to function as a co-activator for certain homeobox transcription factors which are critical to nervous system development and organization  Furthermore, RNA transcripts can interfere with the functionality of the transcriptional complex by interacting or associating with RNA polymerases during the transcription or loading processes  Moreover, non-coding RNAs like SINEs can bind or interact directly with the DNA duplex coding the gene and thus prevent its transcription Also, many non-coding RNAs are distributed near protein-coding genes, often in the reverse direction  This is especially true for short-interspersed nuclear elements as seen in Usmanova et al  These non-coding RNAs, which lie adjacent to or overlap gene-sets provide a mechanism by which transcription factors and machinery can be recruited to increase or repress the transcription of local genes  The particular example of SINEs potentially recruiting the YY1 polycomb transcriptional repressor is discussed above   Alternatively, it also provides a mechanism by which local gene expression can be curtailed and regulated because the transcriptional complexes can hinder or prevent nearby genes from being transcribed  There is research to suggest that this phenomenon is particularly seen in the gene-regulation of pluripotent cells In conclusion, non-coding RNAs such as SINEs are capable of affecting gene expression on a multitude of different levels and in different ways  Short-interspersed nuclear elements are believed to be deeply integrated into a complex regulatory network capable of fine-tuning gene expression across the eukaryotic genome 

Propagation and regulation
The RNA coded by the short-interspersed nuclear element does not code for any protein product but is nonetheless reverse-transcribed and inserted back into an alternate region in the genome  For this reason, short interspersed nuclear elements are believed to have co-evolved with long interspersed nuclear element (LINEs), as LINEs do in fact encode protein products which enable them to be reverse- transcribed and integrated back into the genome   SINEs are  believed to have co-opted the proteins coded by LINEs which are contained in 2 reading frames  Open reading frame 1 (ORF 1)  encodes a protein which binds to RNA and acts as a chaperone to facilitate and maintain the LINE protein-RNA complex structure  Open reading frame 2 (ORF 2) codes a protein which possesses both endonuclease and reverse transcriptase activities  This enables the LINE mRNA to be reverse-transcribed into DNA and integrated into the genome based on the sequence-motifs recognized by the protein's endonuclease domain 
LINE-1 (L1) is transcribed and retrotransposed most frequently in the germ-line and during early development; as a result SINEs move around the genome most during these periods  SINE transcription is down-regulated by transcription factors in somatic cells after early development, though stress can cause up-regulation of normally silent SINEs  SINEs can be transferred between individuals or species via horizontal transfer through a viral vector SINEs are known to share sequence homology with LINES which gives a basis by which the LINE machinery can reverse transcribe and integrate SINE transcripts  Alternately, some SINEs are believed to use a much more complex system of integrating back into the genome; this system involves the use random double-stranded DNA breaks (rather than the endonuclease coded by related long-interspersed nuclear elements creating an insertion-site)  These DNA breaks are utilized to prime reverse transcriptase, ultimately integrating the SINE transcript back into the genome  SINEs nonetheless depend on enzymes coded by other DNA elements and are thus known as non-autonomous retrotransposons as they depend on the machinery of LINEs, which are known as autonomous retrotransposons <The theory that short-interspersed nuclear elements have evolved to utilize the retrotransposon machinery of long-interspersed nuclear elements is supported by studies which examine the presence and distribution of LINEs and SINEs in taxa of different species  For example, LINEs and SINEs in rodents and primates show very strong homology at the insertion-site motif  Such evidence is a basis for the proposed mechanism in which integration of the SINE transcript can be co-opted with LINE-coded protein products  This is specifically demonstrated by a detailed analysis of over 20 rodent species profiled LINEs and SINEs, mainly L1s and B1s respectively; these are families of LINEs and SINEs found at high frequencies in rodents along with other mammals  The study sought to provide phylogenetic clarity within the context of LINE and SINE activity 
The study arrived at a candidate taxa believed to be the first instance of L1 LINE extinction; it expectedly discovered that there was no evidence to suggest that B1 SINE activity occurred in species which did not have L1 LINE activity  Also, the study suggested that B1 short-interspersed nuclear element silencing in fact occurred before L1 long-interspersed nuclear element extinction; this is due to the fact that B1 SINEs are silenced in the genus most-closely related to the genus which does not contain active L1 LINEs (though the genus with B1 SINE silencing still contains active L1 LINEs)   Another genus was also found which similarly contained active L1 long-interspersed nuclear elements but did not contain B1 short-interspersed nuclear elements; the opposite scenario, in which active B1 SINEs were present in a genus which did not possess active L1 LINEs was not found  This result was expected and strongly supports the theory that SINEs have evolved to co-opt the RNA-binding proteins, endonucleases, and reverse-transcriptases coded by LINEs  In taxa which do not actively transcribe and translate long-interspersed nuclear elements protein-products, SINEs do not have the theoretical foundation by which to retrotranspose within the genome  The results obtained in Rinehart et al  are thus very supportive of the current model of SINE retrotransposition 

Effects of SINE transposition
Insertion of a SINE upstream of a coding region may result in exon shuffling or changes to the regulatory region of the gene  Insertion of a SINE into the coding sequence of a gene can have deleterious effects and unregulated transposition can cause genetic disease  The transposition and recombination of SINEs and other active nuclear elements is thought to be one of the major contributions of genetic diversity between lineages during speciation 

Common SINEs
Short-interspersed nuclear elements are believed to have parasitic origins in eukaryotic genomes  These SINEs have mutated and replicated themselves a large number of times on an evolutionary time-scale and thus form many different lineages  Their early evolutionary origin has caused them to be ubiquitous in many eukaryotic lineages 
Alu elements, short-interspersed nuclear element of about 300 nucleotides, are the most common SINE in humans, with >1,000,000 copies throughout the genome, which is over 10 percent of the total genome; this is not uncommon among other species  Alu element copy number differences can be used to distinguish between and construct phylogenies of primate species  Canines differ primarily in their abundance of SINEC_Cf repeats throughout the genome, rather than other gene or allele level mutations  These dog-specific SINEs may code for a splice acceptor site, altering the sequences that appear as exons or introns in each species Apart from mammals, SINEs can reach high copy numbers in a range of species, including nonbony vertebrates (elephant shark) and some fish species (coelacanths)  In plants, SINEs are often restricted to closely related species and have emerged, decayed, and vanished frequently during evolution  Nevertheless, some SINE families such as the Au-SINEs and the Angio-SINEs are unusually widespread across many often unrelated plant species 

Diseases
There are >50 human diseases associated with SINEs  When inserted near or within the exon, SINEs can cause improper splicing, become coding regions, or change the reading frame, often leading to disease phenotypes in humans and other animals  Insertion of Alu elements in the human genome is associated with breast cancer, colon cancer, leukemia, hemophilia, Dent's disease, cystic fibrosis, neurofibromatosis, and many others 

microRNAs
The role of short-interspersed nuclear elements in gene regulation within cells has been supported by multiple studies  One such study examined the correlation between a certain family of SINEs with microRNAs (in zebrafish)  The specific family of SINEs being examined was the Anamnia V-SINEs; this family of short interspersed nuclear elements is often found in the untranslated region of the 3' end of many genes and is present in vertebrate genomes   The study involved a computational analysis in which the genomic distribution and activity of the Anamnia V-SINEs in Danio rerio zebrafish was examined; furthermore, these V-SINEs potential to generate novel microRNA loci was analyzed   It was found that genes which were predicted to possess V-SINEs were targeted by microRNAs with significantly higher hybridization E-values (relative to other areas in the genome)   The genes that had high hybridization E-values were genes particularly involved in metabolic and signaling pathways  Almost all miRNAs identified to have a strong ability to hybridize to putative V-SINE sequence motifs in genes have been identified (in mammals) to have regulatory roles  These results which establish a correlation between short-interspersed nuclear elements and different regulatory microRNAs strongly suggest that V-SINEs have a significant role in attenuating responses to different signals and stimuli related to metabolism, proliferation and differentiation  Many other studies must be undertaken to establish the validity and extent of short-interspersed nuclear element retrotransposons' role in regulatory gene-expression networks  In conclusion, though not much is known about the role and mechanism by which SINEs generate miRNA gene loci  it is generally understood that SINEs have played a significant evolutionary role in the creation of "RNA-genes", this is also touched upon above in SINEs and pseudogenes 
With such evidence suggesting that short-interspersed nuclear elements have been evolutionary sources for microRNA loci generation it is important to further discuss the potential relationships between the two as well as the mechanism by which the microRNA regulates RNA degradation and more broadly, gene expression   A microRNA is a non-coding RNA generally 22 nucleotides in length  This non-protein coding oligonucleotide is itself coded by longer nuclear DNA sequence usually transcribed by RNA polymerase II which is also responsible for the transcription of most mRNAs and snRNAs in eukaryotes   However, some research suggests that some microRNAs that possess upstream short-interspersed nuclear elements are transcribed by RNA polymerase III which is widely implicated in ribosomal RNA and tRNA, two transcripts vital to mRNA translation   This provides an alternate mechanism by which short-interspersed nuclear elements could be interacting with or mediating gene-regulatory networks involving microRNAs 
The regions coding miRNA can be independent RNA-genes often being anti-sense to neighboring protein-coding genes, or can be found within the introns of protein-coding genes  The co-localization of microRNA and protein-coding genes provides a mechanistic foundation by which microRNA regulates gene-expression  Furthermore, Scarpato et al   reveals (as discussed above) that genes predicted to possess short-interspersed nuclear elements (SINEs) through sequence analysis were targeted and hybridized by microRNAs significantly greater than other genes  This provides an evolutionarily path by which the parasitic SINEs were co-opted and utilized to form RNA-genes (such as microRNAs) which have evolved to play a role in complex gene-regulatory networks 
The microRNAs are transcribed as part of longer RNA strands of generally about 80 nucleotides which through complementary base-pairing are able to form hairpin loop structures These structures are recognized and processed in the nucleus by the nuclear protein DiGeorge Syndrome Critical Region 8 (DGCR8) which recruits and associates with the Drosha protein   This complex is responsible for cleaving some of the hair-pin structures from the pre-microRNA which is transported to the cytoplasm  The pre-miRNA is processed by the protein DICER into a double stranded 22 nucleotide   Thereafter, one of the strands is incorporated into a multi-protein RNA-induced silencing complex (RISC)  Among these proteins are proteins from the Argonaute family which are critical to the complex's ability to interact with and repress the translation of the target mRNA Understanding the different ways in which microRNA regulates gene-expression, including mRNA-translation and degradation is key to understanding the potential evolutionary role of SINEs in gene-regulation and in the generation of microRNA loci  This, in addition to SINEs' direct role in regulatory networks (as discussed in SINEs as long non-coding RNAs) is crucial to beginning to understand the relationship between SINEs and certain diseases  Multiple studies have suggested that increased SINE activity is correlated with certain gene-expression profiles and post-transcription regulation of certain genes   In fact, Peterson et al  2013 demonstrated that high SINE RNA expression correlates with post-transcriptional downregulation of BRCA1, a tumor suppressor implicated in multiple forms of cancer, namely breast cancer  Furthermore, studies have established a strong correlation between transcriptional mobilization of SINEs and certain cancers and conditions such as hypoxia; this can be due to the genomic instability caused by SINE activity as well as more direct-downstream effects   SINEs have also been implicated in countless other diseases  In essence, short-interspersed nuclear elements have become deeply integrated in countless regulatory, metabolic and signaling pathways and thus play an inevitable role in causing disease  Much is still to be known about these genomic parasites but it is clear they play a significant role within eukaryotic organisms 

SINEs and pseudogenes
The activity of SINEs however has genetic vestiges which do not seem to play a significant role, positive or negative, and manifest themselves in the genome as pseudogenes   SINEs however should not be mistaken as RNA pseudogenes  In general, pseudogenes are generated when processed mRNAs of protein-coding genes are reverse-transcribed and incorporated back into the genome (RNA pseudogenes are reverse transcribed RNA genes)  Pseudogenes are generally functionless as they descend from processed RNAs independent of their evolutionary-context which includes introns and different regulatory elements which enable transcription and processing  These pseudogenes, though non-functional may in some cases still possess promoters, CpG islands, and other features which enable transcription; they thus can still be transcribed and may possess a role in the regulation of gene expression (like SINEs and other non-coding elements)   Pseudogenes thus differ from SINEs in that they are derived from transcribed- functional RNA whereas SINEs are DNA elements which retrotranspose by co-opting RNA genes transcriptional machinery  However, there are studies which suggest  that retro-transposable elements such as short-interspersed nuclear elements are not only capable of copying themselves in alternate regions in the genome but are also able to do so for random genes too   Thus SINEs can be playing a vital role in the generation of pseudogenes, which themselves are known to be involved in regulatory networks  This is perhaps another means by which SINEs have been able to influence and contribute to gene-regulation 
Passage 2:
Exonuclease VII
The enzyme exodeoxyribonuclease VII (EC 3 1 11 6, Escherichia coli exonuclease VII, E  coli exonuclease VII, endodeoxyribonuclease VII, exodeoxyribonuclease VII) is a bacterial exonuclease enzyme  It is composed of two nonidentical subunits; one large subunit and 4 small ones  that catalyses exonucleolytic cleavage in either 5′- to 3′- or 3′- to 5′-direction to yield nucleoside 5′-phosphates  The large subunit also contains an N-terminal OB-fold domain that binds to nucleic acids 
Passage 3:
Ribosomal protein
A ribosomal protein (r-protein or rProtein) is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation  E  coli, other bacteria and Archaea have a 30S small subunit and a 50S large subunit, whereas humans and yeasts have a 40S small subunit and a 60S large subunit  Equivalent subunits are frequently numbered differently between bacteria, Archaea, yeasts and humans A large part of the knowledge about these organic molecules has come from the study of E  coli ribosomes  All ribosomal proteins have been isolated and many specific antibodies have been produced  These, together with electronic microscopy and the use of certain reactives, have allowed for the determination of the topography of the proteins in the ribosome   More recently, a near-complete (near)atomic picture of the ribosomal proteins is emerging from the latest high-resolution cryo-EM data (including PDB: 5AFI​) 

Conservation
Ribosomal proteins are among the most highly conserved proteins across all life forms  Among the 40 proteins found in various small ribosomal subunits (RPSs), 15 subunits are universally conserved across prokaryotes and eukaryotes  However, 7 subunits are only found in bacteria (bS21, bS6, bS16, bS18, bS20, bS21, and bTHX), while 17 subunits are only found in archaea and eukaryotes  Typically 22 proteins are found in bacterial small subunits and 32 in yeast, human and most likely most other eukaryotic species  Twenty-seven (out of 32) proteins of the eukaryotic small ribosomal subunit proteins are also present in archaea (no ribosomal protein is exclusively found in archaea), confirming that they are more closely related to eukaryotes than to bacteria Among the large ribosomal subunit (RPLs), 18 proteins are universal, i e  found in both bacteria, eukaryotes, and archaea  14 proteins are only found in bacteria, while 27 proteins are only found in archaea and eukaryotes  Again, archaea have no proteins unique to them 

Essentiality
Despite their high conservation over billions of years of evolution, the absence of several ribosomal proteins in certain species shows that ribosomal subunits have been added and lost over the course of evolution  This is also reflected by the fact that several ribosomal proteins do not appear to be essential when deleted  For instance, in E  coli nine ribosomal proteins (uL15, bL21, uL24, bL27, uL29, uL30, bL34, uS9, and uS17) are nonessential for survival when deleted  Taken together with previous results, 22 of the 54 E  coli ribosomal protein genes can be individually deleted from the genome  Similarly, 16 ribosomal proteins (uL1, bL9, uL15, uL22, uL23, bL28, uL29, bL32, bL33 1, bL33 2, bL34, bL35, bL36, bS6, bS20, and bS21) were successfully deleted in Bacillus subtilis  In conjunction with previous reports, 22 ribosomal proteins have been shown to be nonessential in B  subtilis, at least for cell proliferation 

Assembly
In E  coli
The ribosome of E  coli has about 22 proteins in the small subunit (labelled S1 to S22) and 33 proteins in the large subunit (somewhat counter-intuitively called L1 to L36)  All of them are different with three exceptions: one protein is found in both subunits (S20 and L26), L7 and L12 are acetylated and methylated forms of the same protein, and L8 is a complex of L7/L12 and L10  In addition, L31 is known to exist in two forms, the full length at 7 9 kilodaltons (kDa) and fragmented at 7 0 kDa  This is why the number of proteins in a ribosome is of 56  Except for S1 (with a molecular weight of 61 2 kDa), the other proteins range in weight between 4 4 and 29 7 kDa Recent de novo proteomics experiments where the authors characterized in vivo ribosome-assembly intermediates and associated assembly factors from wild-type Escherichia coli cells using a general quantitative mass spectrometry (qMS) approach have confirmed the presence of all the known small and large subunit components and have identified a total of 21 known and potentially new ribosome-assembly-factors that co-localise with various ribosomal particles 

Disposition in the small ribosomal subunit
In the small (30S) subunit of E  coli ribosomes, the proteins denoted uS4, uS7, uS8, uS15, uS17, bS20 bind independently to 16S rRNA  After assembly of these primary binding proteins, uS5, bS6, uS9, uS12, uS13, bS16, bS18, and uS19 bind to the growing ribosome  These proteins also potentiate the addition of uS2, uS3, uS10, uS11, uS14, and bS21  Protein binding to helical junctions is important for initiating the correct tertiary fold of RNA and to organize the overall structure  Nearly all the proteins contain one or more globular domains  Moreover, nearly all contain long extensions that can contact the RNA in far-reaching regions  Additional stabilization results from the proteins' basic residues, as these neutralize the charge repulsion of the RNA backbone  Protein–protein interactions also exist to hold structure together by electrostatic and hydrogen bonding interactions  Theoretical investigations pointed to correlated effects of protein-binding onto binding affinities during the assembly processIn one study, the net charges (at pH 7 4) of the ribosomal proteins comprising the highly conserved S10-spc cluster were found to have an inverse relationship with the halophilicity/halotolerance levels in bacteria and archaea  In non-halophilic bacteria, the S10-spc proteins are generally basic, contrasting with the overall acidic whole proteomes of the extremely halophiles  The universal uL2 lying in the oldest part of the ribosome, is always positively charged irrespective of the strain/organism it belongs to 

In eukaryotes
Ribosomes in eukaryotes contain 79–80 proteins and four ribosomal RNA (rRNA) molecules 
General or specialized chaperones solubilize the ribosomal proteins and facilitate their import into the nucleus  Assembly of the eukaryotic ribosome appears to be driven by the ribosomal proteins in vivo when assembly is also aided by chaperones   Most ribosomal proteins assemble with rRNA co-transcriptionally, becoming associated more stably as assembly proceeds, and the active sites of both subunits are constructed last 

Table of ribosomal proteins
In the past, different nomenclatures were used for the same ribosomal protein in different organisms  Not only were the names not consistent across domains; the names also differed between organisms within a domain, such as humans and S  cervisiae, both eukaryotes  This was due to researchers assigning names before the sequences were known, causing trouble for later research  The following tables use the unified nomenclature by Ban et al , 2014  The same nomenclature is used by UniProt's "family" curation In general, cellular ribosomal proteins are to be called simply using the cross domain name, e g  "uL14" for what is currently called L23 in humans  A suffix is used for the organellar versions, so that "uL14m" refers to the human mitochondrial uL14 (MRPL14)  Organelle-specific proteins use their own cross-domain prefixes, for example "mS33" for MRPS33: Table S3,S4  and "cL37" for PSRP5 : Table S2,S3  (See the two proceeding citations, also partially by Ban N, for the organelle nomenclatures )

See also
Alpha operon ribosome binding site
Ribosomal protein L20 leader
Mitochondrial ribosome, for a list of its protein subunits
Passage 4:
Nuclear cap-binding protein complex
Nuclear cap-binding protein complex is a RNA-binding protein which binds to the 5' cap of pre-mRNA  The cap and nuclear cap-binding protein have many functions in mRNA biogenesis including splicing, 3'-end formation by stabilizing the interaction of the 3'-end processing machinery, nuclear export and protection of the transcripts from nuclease degradation  When RNA is exported to the cytoplasm the nuclear cap-binding protein complex is replaced by cytoplasmic cap binding complex  The nuclear cap-binding complex is a functional heterodimer and composed of Cbc1/Cbc2 in yeast and CBC20/CBC80 in multicellular eukaryotes  Human nuclear cap-binding protein complex shows the large subunit, CBC80 consists of 757 amino acid residues  Its secondary structure contains approximately sixty percent of helical and one percent of beta sheet in the strand  The small subunit, CBC20 has 98 amino acid residues  Its secondary structure contains approximately twenty percent of helical and twenty-four percent of beta sheet in the strand  Human nuclear cap-binding protein complex plays important role in the maturation of pre-mRNA and in uracil-rich small nuclear RNA 
Passage 5:
Ribozyme
Ribozymes (ribonucleic acid enzymes) are RNA molecules that have the ability to catalyze specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes  The 1982 discovery of ribozymes demonstrated that RNA can be both genetic material (like DNA) and a biological catalyst (like protein enzymes), and contributed to the RNA world hypothesis, which suggests that RNA may have been important in the evolution of prebiotic self-replicating systems The most common activities of natural or in vitro evolved ribozymes are the cleavage (or ligation) of RNA and DNA and peptide bond formation  For example, the smallest ribozyme known (GUGGC-3') can aminoacylate a GCCU-3' sequence in the presence of PheAMP  Within the ribosome, ribozymes function as part of the large subunit ribosomal RNA to link amino acids during protein synthesis  They also participate in a variety of RNA processing reactions, including RNA splicing, viral replication, and transfer RNA biosynthesis  Examples of ribozymes include the hammerhead ribozyme, the VS ribozyme, leadzyme, and the hairpin ribozyme 
Researchers who are investigating the origins of life through the RNA world hypothesis have been working on discovering a ribozyme with the capacity to self-replicate, which would require it to have the ability to catalytically synthesize polymers of RNA  This should be able to happen in prebiotically plausible conditions with high rates of copying accuracy to prevent degradation of information but also allowing for the occurrence of occasional errors during the copying process to allow for Darwinian evolution to proceed Attempts have been made to develop ribozymes as therapeutic agents, as enzymes which target defined RNA sequences for cleavage, as biosensors, and for applications in functional genomics and gene discovery 

Discovery
Before the discovery of ribozymes, enzymes—which are defined as catalytic proteins—were the only known biological catalysts  In 1967, Carl Woese, Francis Crick, and Leslie Orgel were the first to suggest that RNA could act as a catalyst  This idea was based upon the discovery that RNA can form complex secondary structures  These ribozymes were found in the intron of an RNA transcript, which removed itself from the transcript, as well as in the RNA component of the RNase P complex, which is involved in the maturation of pre-tRNAs  In 1989, Thomas R  Cech and Sidney Altman shared the Nobel Prize in chemistry for their "discovery of catalytic properties of RNA"  The term ribozyme was first introduced by Kelly Kruger et al  in a paper published in Cell in 1982 It had been a firmly established belief in biology that catalysis was reserved for proteins  However, the idea of RNA catalysis is motivated in part by the old question regarding the origin of life: Which comes first, enzymes that do the work of the cell or nucleic acids that carry the information required to produce the enzymes? The concept of "ribonucleic acids as catalysts" circumvents this problem  RNA, in essence, can be both the chicken and the egg In the 1980s, Thomas Cech, at the University of Colorado Boulder, was studying the excision of introns in a ribosomal RNA gene in Tetrahymena thermophila  While trying to purify the enzyme responsible for the splicing reaction, he found that the intron could be spliced out in the absence of any added cell extract  As much as they tried, Cech and his colleagues could not identify any protein associated with the splicing reaction  After much work, Cech proposed that the intron sequence portion of the RNA could break and reform phosphodiester bonds  At about the same time, Sidney Altman, a professor at Yale University, was studying the way tRNA molecules are processed in the cell when he and his colleagues isolated an enzyme called RNase-P, which is responsible for conversion of a precursor tRNA into the active tRNA  Much to their surprise, they found that RNase-P contained RNA in addition to protein and that RNA was an essential component of the active enzyme  This was such a foreign idea that they had difficulty publishing their findings  The following year, Altman demonstrated that RNA can act as a catalyst by showing that the RNase-P RNA subunit could catalyze the cleavage of precursor tRNA into active tRNA in the absence of any protein component 
Since Cech's and Altman's discovery, other investigators have discovered other examples of self-cleaving RNA or catalytic RNA molecules  Many ribozymes have either a hairpin – or hammerhead – shaped active center and a unique secondary structure that allows them to cleave other RNA molecules at specific sequences  It is now possible to make ribozymes that will specifically cleave any RNA molecule  These RNA catalysts may have pharmaceutical applications  For example, a ribozyme has been designed to cleave the RNA of HIV  If such a ribozyme were made by a cell, all incoming virus particles would have their RNA genome cleaved by the ribozyme, which would prevent infection 

Structure and mechanism
Despite having only four choices for each monomer unit (nucleotides), compared to 20 amino acid side chains found in proteins, ribozymes have diverse structures and mechanisms  In many cases they are able to mimic the mechanism used by their protein counterparts  For example, in self cleaving ribozyme RNAs, an in-line SN2 reaction is carried out using the 2’ hydroxyl group as a nucleophile attacking the bridging phosphate and causing 5’ oxygen of the N+1 base to act as a leaving group  In comparison, RNase A, a protein that catalyzes the same reaction, uses a coordinating histidine and lysine to act as a base to attack the phosphate backbone Like many protein enzymes, metal binding is also critical to the function of many ribozymes  Often these interactions use both the phosphate backbone and the base of the nucleotide, causing drastic conformational changes  There are two mechanism classes for the cleavage of a phosphodiester backbone in the presence of metal  In the first mechanism, the internal 2’- OH group attacks the phosphorus center in a SN2 mechanism  Metal ions promote this reaction by first coordinating the phosphate oxygen and later stabling the oxyanion  The second mechanism also follows a SN2 displacement, but the nucleophile comes from water or exogenous hydroxyl groups rather than RNA itself  The smallest ribozyme is UUU, which can promote the cleavage between G and A of the GAAA tetranucleotide via the first mechanism in the presence of Mn2+  The reason why this trinucleotide (rather than the complementary tetramer) catalyzes this reaction may be because the UUU-AAA pairing is the weakest and most flexible trinucleotide among the 64 conformations, which provides the binding site for Mn2+ Phosphoryl transfer can also be catalyzed without metal ions  For example, pancreatic ribonuclease A and hepatitis delta virus (HDV) ribozymes can catalyze the cleavage of RNA backbone through acid-base catalysis without metal ions  Hairpin ribozyme can also catalyze the self-cleavage of RNA without metal ions, but the mechanism for this is still unclear Ribozyme can also catalyze the formation of peptide bond between adjacent amino acids by lowering the activation entropy 

Activities
Although ribozymes are quite rare in most cells, their roles are sometimes essential to life  For example, the functional part of the ribosome, the biological machine that translates RNA into proteins, is fundamentally a ribozyme, composed of RNA tertiary structural motifs that are often coordinated to metal ions such as Mg2+ as cofactors  In a model system, there is no requirement for divalent cations in a five-nucleotide RNA catalyzing trans-phenylalanation of a four-nucleotide substrate with 3 base pairs complementary with the catalyst, where the catalyst/substrate were devised by truncation of the C3 ribozyme The best-studied ribozymes are probably those that cut themselves or other RNAs, as in the original discovery by Cech and Altman  However, ribozymes can be designed to catalyze a range of reactions, many of which may occur in life but have not been discovered in cells RNA may catalyze folding of the pathological protein conformation of a prion in a manner similar to that of a chaperonin 

Ribozymes and the origin of life
RNA can also act as a hereditary molecule, which encouraged Walter Gilbert to propose that in the distant past, the cell used RNA as both the genetic material and the structural and catalytic molecule rather than dividing these functions between DNA and protein as they are today; this hypothesis is known as the "RNA world hypothesis" of the origin of life  Since nucleotides and RNA (and thus ribozymes) can arise by inorganic chemicals, they are candidates for the first enzymes, and in fact, the first "replicators" (i e , information-containing macro-molecules that replicate themselves)  An example of a self-replicating ribozyme that ligates two substrates to generate an exact copy of itself was described in 2002 
The discovery of the catalytic activity of RNA solved the "chicken and egg" paradox of the origin of life, solving the problem of origin of peptide and nucleic acid central dogma  According to this scenario, at the origin of life, all enzymatic activity and genetic information encoding was done by one molecule: RNA 
Ribozymes have been produced in the laboratory that are capable of catalyzing the synthesis of other RNA molecules from activated monomers under very specific conditions, these molecules being known as RNA polymerase ribozymes  The first RNA polymerase ribozyme was reported in 1996, and was capable of synthesizing RNA polymers up to 6 nucleotides in length  Mutagenesis and selection has been performed on an RNA ligase ribozyme from a large pool of random RNA sequences, resulting in isolation of the improved "Round-18" polymerase ribozyme in 2001 which could catalyze RNA polymers now up to 14 nucleotides in length  Upon application of further selection on the Round-18 ribozyme, the B6 61 ribozyme was generated and was able to add up to 20 nucleotides to a primer template in 24 hours, until it decomposes by cleavage of its phosphodiester bonds The rate at which ribozymes can polymerize an RNA sequence multiples substantially when it takes place within a micelle The next ribozyme discovered was the "tC19Z" ribozyme, which can add up to 95 nucleotides with a fidelity of 0 0083 mutations/nucleotide  Next, the "tC9Y" ribozyme was discovered by researchers and was further able to synthesize RNA strands up to 206 nucleotides long in the eutectic phase conditions at below-zero temperature, conditions previously shown to promote ribozyme polymerase activity The RNA polymerase ribozyme (RPR) called tC9-4M was able to polymerize RNA chains longer than itself (i e  longer than 177 nt) in magnesium ion concentrations close to physiological levels, whereas earlier RPRs required prebiotically implausible concentrations of up to 200 mM  The only factor required for it to achieve this was the presence of a very simple amino acid polymer called lysine decapeptide The most complex RPR synthesized by that point was called 24-3, which was newly capable of polymerizing the sequences of a substantial variety of nucleotide sequences and navigating through complex secondary structures of RNA substrates inaccessible to previous ribozymes  In fact, this experiment was the first to use a ribozyme to synthesize a tRNA molecule  Starting with the 24-3 ribozyme, Tjhung et al  applied another fourteen rounds of selection to obtain an RNA polymerase ribozyme by in vitro evolution termed '38-6' that has an unprecedented level of activity in copying complex RNA molecules  However, this ribozyme is unable to copy itself and its RNA products have a high mutation rate  In a subsequent study, the researchers began with the 38-6 ribozyme and applied another 14 rounds of selection to generate the '52-2' ribozyme, which compared to 38-6, was again many times more active and could begin generating detectable and functional levels of the class I ligase, although it was still limited in its fidelity and functionality in comparison to copying of the same template by proteins such as the T7 RNA polymerase An RPR called t5(+1) adds triplet nucleotides at a time instead of just one nucleotide at a time  This heterodimeric RPR can navigate secondary structures inaccessible to 24-3, including hairpins  In the initial pool of RNA variants derived only from a previously synthesized RPR known as the Z RPR, two sequences separately emerged and evolved to be mutualistically dependent on each other  The Type 1 RNA evolved to be catalytically inactive, but complexing with the Type 5 RNA boosted its polymerization ability and enabled intermolecular interactions with the RNA template substrate obviating the need to tether the template directly to the RNA sequence of the RPR, which was a limitation of earlier studies  Not only did t5(+1) not need tethering to the template, but a primer was not needed either as t5(+1) had the ability to polymerize a template in both 3' → 5' and 5' 3 → 3' directions A highly evolved RNA polymerase ribozyme was able to function as a reverse transcriptase, that is, it can synthesize a DNA copy using an RNA template  Such an activity is considered to have been crucial for the transition from RNA to DNA genomes during the early history of life on earth  Reverse transcription capability could have arisen as a secondary function of an early RNA-dependent RNA polymerase ribozyme 
An RNA sequence that folds into a ribozyme is capable of invading duplexed RNA, rearranging into an open holopolymerase complex, and then searching for a specific RNA promoter sequence, and upon recognition rearrange again into a processive form that polymerizes a complementary strand of the sequence  This ribozyme is capable of extending duplexed RNA by up to 107 nucleotides, and does so without needing to tether the sequence being polymerized 

Artificial ribozymes
Since the discovery of ribozymes that exist in living organisms, there has been interest in the study of new synthetic ribozymes made in the laboratory  For example, artificially produced self-cleaving RNAs with good enzymatic activity have been produced  Tang and Breaker isolated self-cleaving RNAs by in vitro selection of RNAs originating from random-sequence RNAs  Some of the synthetic ribozymes that were produced had novel structures, while some were similar to the naturally occurring hammerhead ribozyme 
In 2015, researchers at Northwestern University and the University of Illinois Chicago engineered a tethered ribosome that works nearly as well as the authentic cellular component that produces all the proteins and enzymes within the cell  Called Ribosome-T, or Ribo-T, the artificial ribosome was created by Michael Jewett and Alexander Mankin  The techniques used to create artificial ribozymes involve directed evolution  This approach takes advantage of RNA's dual nature as both a catalyst and an informational polymer, making it easy for an investigator to produce vast populations of RNA catalysts using polymerase enzymes  The ribozymes are mutated by reverse transcribing them with reverse transcriptase into various cDNA and amplified with error-prone PCR  The selection parameters in these experiments often differ  One approach for selecting a ligase ribozyme involves using biotin tags, which are covalently linked to the substrate  If a molecule possesses the desired ligase activity, a streptavidin matrix can be used to recover the active molecules 
Lincoln and Joyce used in vitro evolution to develop ribozyme ligases capable of self-replication in about an hour, via the joining of pre-synthesized highly complementary oligonucleotides Although not true catalysts, the creation of artificial self-cleaving riboswitches, termed aptazymes, has also been an active area of research  Riboswitches are regulatory RNA motifs that change their structure in response to a small molecule ligand to regulate translation  While there are many known natural riboswitches that bind a wide array of metabolites and other small organic molecules, only one ribozyme based on a riboswitch has been described: glmS  Early work in characterizing self-cleaving riboswitches was focused on using theophylline as the ligand  In these studies, an RNA hairpin is formed which blocks the ribosome binding site, thus inhibiting translation  In the presence of the ligand, in these cases theophylline, the regulatory RNA region is cleaved off, allowing the ribosome to bind and translate the target gene  Much of this RNA engineering work was based on rational design and previously determined RNA structures rather than directed evolution as in the above examples  More recent work has broadened the ligands used in ribozyme riboswitches to include thymine pyrophosphate  Fluorescence-activated cell sorting has also been used to engineering aptazymes 

Applications
Ribozymes have been proposed and developed for the treatment of disease through gene therapy  One major challenge of using RNA-based enzymes as a therapeutic is the short half-life of the catalytic RNA molecules in the body  To combat this, the 2’ position on the ribose is modified to improve RNA stability  One area of ribozyme gene therapy has been the inhibition of RNA-based viruses 
A type of synthetic ribozyme directed against HIV RNA called gene shears has been developed and has entered clinical testing for HIV infection Similarly, ribozymes have been designed to target the hepatitis C virus RNA, SARS coronavirus (SARS-CoV), Adenovirus and influenza A and B virus RNA  The ribozyme is able to cleave the conserved regions of the virus's genome, which has been shown to reduce the virus in mammalian cell culture  Despite these efforts by researchers, these projects have remained in the preclinical stage 

Known ribozymes
Well-validated naturally occurring ribozyme classes:

See also
Notes and references
Further reading
External links
Tom Cech's Short Talk: "Discovering Ribozymes"
Passage 6:
Ribosome
Ribosomes () are macromolecular machines, found within all  cells, that perform biological protein synthesis (mRNA translation)  Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to form polypeptide chains  Ribosomes consist of two major components: the small and large ribosomal subunits  Each subunit consists of one or more ribosomal RNA (rRNA) molecules and many ribosomal proteins (RPs or r-proteins)  The ribosomes and associated molecules are also known as the translational apparatus 

Overview
The sequence of DNA that encodes the sequence of the amino acids in a protein is transcribed into a messenger RNA chain  Ribosomes bind to messenger RNAs and use their sequences for determining the correct sequence of amino acids to generate a given protein  Amino acids are selected and carried to the ribosome by transfer RNA (tRNA) molecules, which enter the ribosome and bind to the messenger RNA chain via an anti-codon stem loop  For each coding triplet (codon) in the messenger RNA, there is a unique transfer RNA that must have the exact anti-codon match, and carries the correct amino acid for incorporating into a growing polypeptide chain  Once the protein is produced, it can then fold to produce a functional three-dimensional structure 
A ribosome is made from complexes of RNAs and proteins and is therefore a ribonucleoprotein complex  Each ribosome is composed of small (30S) and large (50S) components, called subunits, which are bound to each other:

(30S) has mainly a decoding function and is also bound to the mRNA
(50S) has mainly a catalytic function and is also bound to the aminoacylated tRNAs The synthesis of proteins from their building blocks takes place in four phases: initiation, elongation, termination, and recycling  The start codon in all mRNA molecules has the sequence AUG  The stop codon is one of UAA, UAG, or UGA; since there are no tRNA molecules that recognize these codons, the ribosome recognizes that translation is complete  When a ribosome finishes reading an mRNA molecule, the two subunits separate and are usually broken up but can be re-used  Ribosomes are ribozymes, because the catalytic peptidyl transferase activity that links amino acids together is performed by the ribosomal RNA Ribosomes are often associated with the intracellular membranes that make up the rough endoplasmic reticulum 
Ribosomes from bacteria, archaea and eukaryotes in the three-domain system resemble each other to a remarkable degree, evidence of a common origin  They differ in their size, sequence, structure, and the ratio of protein to RNA  The differences in structure allow some antibiotics to kill bacteria by inhibiting their ribosomes, while leaving human ribosomes unaffected  In all species, more than one ribosome may move along a single mRNA chain at one time (as a polysome), each "reading" a specific sequence and producing a corresponding protein molecule 
The mitochondrial ribosomes of eukaryotic cells functionally resemble many features of those in bacteria, reflecting the likely evolutionary origin of mitochondria 

Discovery
Ribosomes were first observed in the mid-1950s by Romanian-American cell biologist George Emil Palade, using an electron microscope, as dense particles or granules   They were initially called  Palade granules due to their granular structure   The term "ribosome" was proposed in 1958:

During the course of the symposium a semantic difficulty became apparent  To some of the participants, "microsomes" mean the ribonucleoprotein particles of the microsome fraction contaminated by other protein and lipid material; to others, the microsomes consist of protein and lipid contaminated by particles  The phrase "microsomal particles" does not seem adequate, and "ribonucleoprotein particles of the microsome fraction" is much too awkward  During the meeting, the word "ribosome" was suggested, which has a very satisfactory name and a pleasant sound  The present confusion would be eliminated if "ribosome" were adopted to designate ribonucleoprotein particles in sizes ranging from 35 to 100S 
Albert Claude, Christian de Duve, and George Emil Palade were jointly awarded the Nobel Prize in Physiology or Medicine, in 1974, for the discovery of the ribosome  The Nobel Prize in Chemistry 2009 was awarded to Venkatraman Ramakrishnan, Thomas A  Steitz and Ada E  Yonath for determining the detailed structure and mechanism of the ribosome 

Structure
The ribosome is a complex cellular machine  It is largely made up of specialized RNA known as ribosomal RNA (rRNA) as well as dozens of distinct proteins (the exact number varies slightly between species)  The ribosomal proteins and rRNAs are arranged into two distinct ribosomal pieces of different sizes, known generally as the large and small subunit of the ribosome  Ribosomes consist of two subunits that fit together (Figure 2) and work as one to translate the mRNA into a polypeptide chain during protein synthesis (Figure 1)  Because they are formed from two subunits of non-equal size, they are slightly longer in the axis than in diameter 

Prokaryotic ribosomes
Prokaryotic ribosomes are around 20 nm (200 Å) in diameter and are composed of 65% rRNA and 35% ribosomal proteins  Eukaryotic ribosomes are between 25 and 30 nm (250–300 Å) in diameter with an rRNA-to-protein ratio that is close to 1  Crystallographic work has shown that there are no ribosomal proteins close to the reaction site for polypeptide synthesis  This suggests that the protein components of ribosomes do not directly participate in peptide bond formation catalysis, but rather that these proteins act as a scaffold that may enhance the ability of rRNA to synthesize protein (See: Ribozyme) 

The ribosomal subunits of prokaryotes and eukaryotes are quite similar The unit of measurement used to describe the ribosomal subunits and the rRNA fragments is the Svedberg unit, a measure of the rate of sedimentation in centrifugation rather than size  This accounts for why fragment names do not add up: for example, bacterial 70S ribosomes are made of 50S and 30S subunits 
Prokaryotes have 70S ribosomes, each consisting of a small (30S) and a large (50S) subunit  E  coli, for example, has a 16S RNA subunit (consisting of 1540 nucleotides) that is bound to 21 proteins  The large subunit is composed of a 5S RNA subunit (120 nucleotides), a 23S RNA subunit (2900 nucleotides) and 31 proteins 
Affinity label for the tRNA binding sites on the E  coli ribosome allowed the identification of A and P site proteins most likely associated with the peptidyltransferase activity; labelled proteins are L27, L14, L15, L16, L2; at least L27 is located at the donor site, as shown by E  Collatz and A P  Czernilofsky  Additional research has demonstrated that the S1 and S21 proteins, in association with the 3′-end of 16S ribosomal RNA, are involved in the initiation of translation 

Archaeal ribosomes
Archaeal ribosomes share the same general dimensions of bacteria ones, being a 70S ribosome made up from a 50S large subunit, a 30S small subunit, and containing three rRNA chains  However, on the sequence level, they are much closer to eukaryotic ones than to bacterial ones  Every extra ribosomal protein archaea have compared to bacteria has a eukaryotic counterpart, while no such relation applies between archaea and bacteria 

Eukaryotic ribosomes
Eukaryotes have 80S ribosomes located in their cytosol, each consisting of a small (40S) and large (60S) subunit  Their 40S subunit has an 18S RNA (1900 nucleotides) and 33 proteins  The large subunit is composed of a 5S RNA (120 nucleotides), 28S RNA (4700 nucleotides), a 5 8S RNA (160 nucleotides) subunits and 49 proteins 
During 1977, Czernilofsky published research that used affinity labeling to identify tRNA-binding sites on rat liver ribosomes  Several proteins, including L32/33, L36, L21, L23, L28/29 and L13 were implicated as being at or near the peptidyl transferase center 

Plastoribosomes and mitoribosomes
In eukaryotes, ribosomes are present in mitochondria (sometimes called mitoribosomes) and in plastids such as chloroplasts (also called plastoribosomes)  They also consist of large and small subunits bound together with proteins into one 70S particle  These ribosomes are similar to those of bacteria and these organelles are thought to have originated as symbiotic bacteria  Of the two, chloroplastic ribosomes are closer to bacterial ones than mitochondrial ones are  Many pieces of ribosomal RNA in the mitochondria are shortened, and in the case of 5S rRNA, replaced by other structures in animals and fungi  In particular, Leishmania tarentolae has a minimalized set of mitochondrial rRNA  In contrast, plant mitoribosomes have both extended rRNA and additional proteins as compared to bacteria, in particular, many pentatricopetide repeat proteins The cryptomonad and chlorarachniophyte algae may contain a nucleomorph that resembles a vestigial eukaryotic nucleus  Eukaryotic 80S ribosomes may be present in the compartment containing the nucleomorph 

Making use of the differences
The differences between the bacterial and eukaryotic ribosomes are exploited by pharmaceutical chemists to create antibiotics that can destroy a bacterial infection without harming the cells of the infected person  Due to the differences in their structures, the bacterial 70S ribosomes are vulnerable to these antibiotics while the eukaryotic 80S ribosomes are not  Even though mitochondria possess ribosomes similar to the bacterial ones, mitochondria are not affected by these antibiotics because they are surrounded by a double membrane that does not easily admit these antibiotics into the organelle  A noteworthy counterexample, however, includes the antineoplastic antibiotic chloramphenicol, which successfully inhibits bacterial 50S and eukaryotic mitochondrial 50S ribosomes  Ribosomes in chloroplasts, however, are different: Antibiotic resistance in chloroplast ribosomal proteins is a trait that has to be introduced as a marker, with genetic engineering 

Common properties
The various ribosomes share a core structure, which is quite similar despite the large differences in size  Much of the RNA is highly organized into various tertiary structural motifs, for example pseudoknots that exhibit coaxial stacking  The extra RNA in the larger ribosomes is in several long continuous insertions, such that they form loops out of the core structure without disrupting or changing it  All of the catalytic activity of the ribosome is carried out by the RNA; the proteins reside on the surface and seem to stabilize the structure 

High-resolution structure
The general molecular structure of the ribosome has been known since the early 1970s  In the early 2000s, the structure has been achieved at high resolutions, of the order of a few ångströms 
The first papers giving the structure of the ribosome at atomic resolution were published almost simultaneously in late 2000  The 50S (large prokaryotic) subunit was determined from the archaeon Haloarcula marismortui and the bacterium Deinococcus radiodurans, and the structure of the 30S subunit was determined from Thermus thermophilus  These structural studies were awarded the Nobel Prize in Chemistry in 2009  In May 2001 these coordinates were used to reconstruct the entire T  thermophilus 70S particle at 5 5 Å resolution Two papers were published in November 2005 with structures of the Escherichia coli 70S ribosome  The structures of a vacant ribosome were determined at 3 5 Å resolution using X-ray crystallography  Then, two weeks later, a structure based on cryo-electron microscopy was published, which depicts the ribosome at 11–15 Å resolution in the act of passing a newly synthesized protein strand into the protein-conducting channel 
The first atomic structures of the ribosome complexed with tRNA and mRNA molecules were solved by using X-ray crystallography by two groups independently, at 2 8 Å and at 3 7 Å  These structures allow one to see the details of interactions of the Thermus thermophilus ribosome with mRNA and with tRNAs bound at classical ribosomal sites  Interactions of the ribosome with long mRNAs containing Shine-Dalgarno sequences were visualized soon after that at 4 5–5 5 Å resolution In 2011, the first complete atomic structure of the eukaryotic 80S ribosome from the yeast Saccharomyces cerevisiae   was obtained by crystallography  The model reveals the architecture of eukaryote-specific elements and their interaction with the universally conserved core  At the same time, the complete model of a eukaryotic 40S ribosomal structure in Tetrahymena thermophila was published and described the structure of the 40S subunit, as well as much about the 40S subunit's interaction with eIF1 during translation initiation  Similarly, the eukaryotic 60S subunit structure was also determined from Tetrahymena thermophila in complex with eIF6 

Function
Ribosomes are minute particles consisting of RNA and associated proteins that function to synthesize proteins  Proteins are needed for many cellular functions such as repairing damage or directing chemical processes  Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum  Their main function is to convert genetic code into an amino acid sequence and to build protein polymers from amino acid monomers 
Ribosomes act as catalysts in two extremely important biological processes called peptidyl transfer and peptidyl hydrolysis  The "PT center is responsible for producing protein bonds during protein elongation" In summary, ribosomes have two main functions: Decoding the message, and the formation of peptide bonds  These two functions reside in the ribosomal subunits  Each subunit is made of one or more rRNAs and many r-proteins  The small subunit (30S in bacteria and archaea, 40S in eukaryotes) has the decoding function, whereas the large subunit (50S in bacteria and archaea, 60S in eukaryotes) catalyzes the formation of peptide bonds, referred to as the peptidyl-transferase activity  The bacterial (and archaeal) small subunit contains the 16S rRNA and 21 r-proteins (Escherichia coli), whereas the eukaryotic small subunit contains the 18S rRNA and 32 r-proteins (Saccharomyces cerevisiae; although the numbers vary between species)  The bacterial large subunit contains the 5S and 23S rRNAs and 34 r-proteins (E  coli), with the eukaryotic large subunit containing the 5S, 5 8S, and 25S / 28S rRNAs and 46 r-proteins (S  cerevisiae; again, the exact numbers vary between species) 

Translation
Ribosomes are the workplaces of protein biosynthesis, the process of translating mRNA into protein  The mRNA comprises a series of codons which are decoded by the ribosome so as to make the protein  Using the mRNA as a template, the ribosome traverses each codon (3 nucleotides) of the mRNA, pairing it with the appropriate amino acid provided by an aminoacyl-tRNA  Aminoacyl-tRNA contains a complementary anticodon on one end and the appropriate amino acid on the other  For fast and accurate recognition of the appropriate tRNA, the ribosome utilizes large conformational changes (conformational proofreading)  The small ribosomal subunit, typically bound to an aminoacyl-tRNA containing the first amino acid methionine, binds to an AUG codon on the mRNA and recruits the large ribosomal subunit  The ribosome contains three RNA binding sites, designated A, P, and E  The A-site binds an aminoacyl-tRNA or termination release factors; the P-site binds a peptidyl-tRNA (a tRNA bound to the poly-peptide chain); and the E-site (exit) binds a free tRNA  Protein synthesis begins at a start codon AUG near the 5' end of the mRNA  mRNA binds to the P site of the ribosome first  The ribosome recognizes the start codon by using the Shine-Dalgarno sequence of the mRNA in prokaryotes and Kozak box in eukaryotes 
Although catalysis of the peptide bond involves the C2 hydroxyl of RNA's P-site adenosine in a proton shuttle mechanism, other steps in protein synthesis (such as translocation) are caused by changes in protein conformations  Since their catalytic core is made of RNA, ribosomes are classified as "ribozymes," and it is thought that they might be remnants of the RNA world 
In Figure 5, both ribosomal subunits (small and large) assemble at the start codon (towards the 5' end of the mRNA)  The ribosome uses tRNA that matches the current codon (triplet) on the mRNA to append an amino acid to the polypeptide chain  This is done for each triplet on the mRNA, while the ribosome moves towards the 3' end of the mRNA  Usually in bacterial cells, several ribosomes are working parallel on a single mRNA, forming what is called a polyribosome or polysome 

Cotranslational folding
The ribosome is known to actively participate in the protein folding  The structures obtained in this way are usually identical to the ones obtained during protein chemical refolding; however, the pathways leading to the final product may be different  In some cases, the ribosome is crucial in obtaining the functional protein form  For example, one of the possible mechanisms of folding of the deeply knotted proteins relies on the ribosome pushing the chain through the attached loop 

Addition of translation-independent amino acids
Presence of a ribosome quality control protein Rqc2 is associated with mRNA-independent protein elongation  This elongation is a result of ribosomal addition (via tRNAs brought by Rqc2) of CAT tails: ribosomes extend the C-terminus of a stalled protein with random, translation-independent sequences of alanines and threonines 

Ribosome locations
Ribosomes are classified as being either "free" or "membrane-bound" 

Free and membrane-bound ribosomes differ only in their spatial distribution; they are identical in structure  Whether the ribosome exists in a free or membrane-bound state depends on the presence of an ER-targeting signal sequence on the protein being synthesized, so an individual ribosome might be membrane-bound when it is making one protein, but free in the cytosol when it makes another protein 
Ribosomes are sometimes referred to as organelles, but the use of the term organelle is often restricted to describing sub-cellular components that include a phospholipid membrane, which ribosomes, being entirely particulate, do not  For this reason, ribosomes may sometimes be described as "non-membranous organelles" 

Free ribosomes
Free ribosomes can move about anywhere in the cytosol, but are excluded from the cell nucleus and other organelles  Proteins that are formed from free ribosomes are released into the cytosol and used within the cell  Since the cytosol contains high concentrations of glutathione and is, therefore, a reducing environment, proteins containing disulfide bonds, which are formed from oxidized cysteine residues, cannot be produced within it 

Membrane-bound ribosomes
When a ribosome begins to synthesize proteins that are needed in some organelles, the ribosome making this protein can become "membrane-bound"  In eukaryotic cells this happens in a region of the endoplasmic reticulum (ER) called the "rough ER"  The newly produced polypeptide chains are inserted directly into the ER by the ribosome undertaking vectorial synthesis and are then transported to their destinations, through the secretory pathway  Bound ribosomes usually produce proteins that are used within the plasma membrane or are expelled from the cell via exocytosis 

Biogenesis
In bacterial cells, ribosomes are synthesized in the cytoplasm through the transcription of multiple ribosome gene operons  In eukaryotes, the process takes place both in the cell cytoplasm and in the nucleolus, which is a region within the cell nucleus  The assembly process involves the coordinated function of over 200 proteins in the synthesis and processing of the four rRNAs, as well as assembly of those rRNAs with the ribosomal proteins 

Origin
The ribosome may have first originated as a protoribosome, possibly containing a peptidyl transferase centre (PTC), in an RNA world, appearing as a self-replicating complex that only later evolved the ability to synthesize proteins when amino acids began to appear  Studies suggest that ancient ribosomes constructed solely of rRNA could have developed the ability to synthesize peptide bonds  In addition, evidence strongly points to ancient ribosomes as self-replicating complexes, where the rRNA in the ribosomes had informational, structural, and catalytic purposes because it could have coded for tRNAs and proteins needed for ribosomal self-replication  Hypothetical cellular organisms with self-replicating RNA but without DNA are called ribocytes (or ribocells) As amino acids gradually appeared in the RNA world under prebiotic conditions, their interactions with catalytic RNA would increase both the range and efficiency of function of catalytic RNA molecules  Thus, the driving force for the evolution of the ribosome from an ancient self-replicating machine into its current form as a translational machine may have been the selective pressure to incorporate proteins into the ribosome's self-replicating mechanisms, so as to increase its capacity for self-replication 

Heterogeneous ribosomes
Ribosomes are compositionally heterogeneous between species and even within the same cell, as evidenced by the existence of cytoplasmic and mitochondria ribosomes within the same eukaryotic cells  Certain researchers have suggested that heterogeneity in the composition of ribosomal proteins in mammals is important for gene regulation, i e , the specialized ribosome hypothesis  However, this hypothesis is controversial and the topic of ongoing research Heterogeneity in ribosome composition was first proposed to be involved in translational control of protein synthesis by Vince Mauro and Gerald Edelman  They proposed the ribosome filter hypothesis to explain the regulatory functions of ribosomes  Evidence has suggested that specialized ribosomes specific to different cell populations may affect how genes are translated  Some ribosomal proteins exchange from the assembled complex with cytosolic copies suggesting that the structure of the in vivo ribosome can be modified without synthesizing an entire new ribosome 
Certain ribosomal proteins are absolutely critical for cellular life while others are not  In budding yeast, 14/78 ribosomal proteins are non-essential for growth, while in humans this depends on the cell of study  Other forms of heterogeneity include post-translational modifications to ribosomal proteins such as acetylation, methylation, and phosphorylation  Arabidopsis, Viral internal ribosome entry sites (IRESs) may mediate translations by compositionally distinct ribosomes  For example, 40S ribosomal units without eS25 in yeast and mammalian cells are unable to recruit the CrPV IGR IRES Heterogeneity of ribosomal RNA modifications plays a significant role in structural maintenance and/or function and most mRNA modifications are found in highly conserved regions  The most common rRNA modifications are pseudouridylation and 2’-O methylation of ribose 

See also
Context 2: Passage 1:
North American Light and Power Company
The North American Light and Power Company was a utility holding company formed in South Bend, Indiana and run since 1916 by its president, Clement Studebaker, Jr , of the family famous for the Studebaker automobiles  The utility company remained a major subsidiary of the North American Company, until that conglomerate's 1940s breakup by the U S  Securities and Exchange Commission (SEC) 

History
Clement Studebaker, Jr  (1871–1932) was born the son of Clement Studebaker (1831–1901), the carriage and automobile manufacturer of South Bend, Indiana In 1911, the company founded by the Studebaker brothers joined forces with Everitt-Metzker-Flanders Company of Detroit to form the Studebaker Corporation  In one of his several executive positions, Clement Studebaker, Jr  served as Vice President of the E-M-F Company By 1916 Clement Studebaker, Jr  had formed the publicly traded North American Light and Power Company, and issued stock, with certificates  printed by the American Banknote Company Clement Studebaker, Jr  also served as President and Chairman of the Board of the Illinois Power and Light Company (and of its subsidiary, the Illinois Traction Company), the South Bend Watch Company, and as Treasurer of the Chicago South Shore and South Bend Railroad 

North American Company
North American Company had once been one of the original stocks in the Dow Jones Industrial Average North American Light and Power remained under the ownership of North American Company for the next decade after Clement's death, as a major subsidiary holding company of other lines  
By 1940, North American Company had become a US$2 3 billion holding company heading up a pyramid of by then 80 companies  It controlled ten major direct subsidiaries in eight of which it owned at least 79%  North American Light and Power Company was by then one of the three major holding companies among the ten direct subsidiaries North American Company was broken up by the SEC, following the United States Supreme Court decision of April 1, 1946 
Passage 2:
Southern Company
Southern Company is an American gas and electric utility holding company based in the southern United States  It is headquartered in Atlanta, Georgia, with executive offices also located in Birmingham, Alabama  The company is the second largest utility company in the U S  in terms of customer base, as of 2021  Through its subsidiaries it serves 9 million gas and electric utility customers in 6 states  Southern Company's regulated regional electric utilities serve a 120,000-square-mile (310,000 km2) territory with 27,000 miles (43,000 km) of distribution lines 

Overview
Southern Company is one of the largest energy providers in the United States and is ranked 126th on the Fortune 500 listing of the largest U S  corporations  The company has approximately 31,300 employees  It has more than 500,000 shareholders (NYSE: SO) and has been traded since September 30, 1949 
Southern Company subsidiaries are operating or developing renewable: solar, wind, and biomass facilities across the U S , as well as the first new nuclear units in the U S  in 30 years at Plant Vogtle near Augusta, Georgia 
Southern Company's three retail operating companies—Alabama Power, Georgia Power, and Mississippi Power—serve 120,000 square miles (310,000 km2) in three states  Southern Power serves wholesale electricity customers across the U S  Southern Company Gas serves utility customers in seven states 
Southern Company owns the following companies:

Alabama Power - operating company, based in Birmingham, Alabama  Serves the southern two-thirds of Alabama 
Georgia Power - operating company, based in Atlanta  Serves all of Georgia, except for mostly rural counties 
Mississippi Power - operating company, based in Gulfport, Mississippi  Serves the Mississippi Gulf Coast 
Southern Company Services (originally named Southern Services, Inc ) - Birmingham, Alabama - Common Services
Southern Linc - cellular telephone provider - Atlanta, Georgia
Southern Nuclear - engineering and operations for nuclear power plants - Birmingham, Alabama  (Southern Company is the majority owner and operator of the Farley, Hatch, and Vogtle nuclear power plants )
Southern Company Generation - fossil fuels and hydro operations - Birmingham, Alabama 
Southern Power - wholesale power generation - Birmingham, Alabama 
Southern Telecom - wholesale fiber optic communications and data services - Atlanta, Georgia 
Southern Company Gas - serves gas utility customers and operates natural gas pipelines - Atlanta, Georgia 
PowerSecure - distributed infrastructure technologies - Wake Forest, North Carolina 
Atlanta Gas Light - provides natural gas delivery service to more than 1 6 million customers in Georgia 
Chattanooga Gas - provides retail natural gas sales and transportation services to approximately 66,000 customers in Hamilton and Bradley counties in southeast Tennessee 
Nicor Gas - Provider of natural gas throughout northern Illinois 
Virginia Natural Gas - Provider of Natural Gas in southeastern Virginia 
Sequent Energy Management - optimizes natural gas assets and effectively utilize transportation and storage services 
Southern Wholesale Energy - markets the retail operating companies' surplus generating capacity to the wholesale market 
Southern Company Transmission - conducts transmission business in accordance with the Southern Companies Open Access Transmission Tariff approved by FERC Prior to 2019, Southern Company also owned Gulf Power, an electric utility based in Pensacola, Florida that serves most of the Florida Panhandle  An agreement was reached in May 2018 to sell Gulf Power to rival utility company NextEra Energy  The sale was completed on January 1, 2019  Gulf Power would become the Northwest Florida division of Florida Power & Light (FPL) in 2021, with the Gulf Power name retired in favor of FPL in 2022 

History
Southern Company can be traced back to 1924, when Southeastern Power & Light was formed as a holding company for Alabama Traction, Light and Power (formed 1906), the immediate forerunner of Alabama Power  Later that year, it formed Mississippi Power as a subsidiary, with Gulf Power following in 1925  In 1926, it merged with Georgia Power (formed 1902)  In 1930, Southeastern Power & Light merged into the Commonwealth & Southern Corporation  The new system included five Northern companies and six Southern companies  However, in the late 1940s Commonwealth & Southern was dissolved to meet the Public Utility Holding Company Act of 1935  Four of Commonwealth & Southern's Deep South operating companies—Alabama Power, Georgia Power, Gulf Power, and Mississippi Power—were deemed to be an integrated system and thus were allowed to remain under common ownership  A new holding company, Southern Company, was incorporated in Delaware on November 9, 1945  It commenced operation in 1949, and moved to Georgia in 1950  In 1954–55, the company was involved in the Dixon-Yates contract with the Atomic Energy Commission, and the associated political controversy In 1981, Southern Company became the first electric utility holding company in 46 years to diversify its operations by forming an unregulated subsidiary  In January 1982, Southern Energy, Inc , began official operations as a global energy company, growing to serve 10 countries on four continents  On April 2, 2001, Southern Company completed the spinoff of Southern Energy as Mirant Corporation 
Another Southern Company subsidiary—Southern Nuclear—began providing services in 1991 to the system's nuclear power plants 
In 1996, Southern Communications Services began providing digital wireless communications services to Southern Company's subsidiaries and also began marketing these services to the public within the Southeast as Southern Linc  Southern Telecom, a telecommunications subsidiary of Southern Company, was founded in 1997  Southern Telecom provides colocation and dark fiber optic lines to network businesses On January 9, 2001, Southern Company received final approval from the Securities and Exchange Commission to form Southern Power, a subsidiary to own, manage and finance wholesale generating assets in the Southeast  The new subsidiary targets wholesale customers 
On July 19, 2002, Southern Company Gas received certification from the Georgia Public Service Commission to enter the retail gas market  After nearly four years of operations, the company was sold and customers transferred to Cobb EMC's newly formed affiliate, Gas South 
In 2011, Southern Company and Turner Renewable Energy purchased a 30 MW solar project from First Solar  Located in Cimarron, New Mexico, it began generating electricity in 2011 In June 2012, the Nacogdoches Generating Facility began its commercial operation  The facility is a 115 MW biomass-fueled electric generating plant, located near Sacul in Nacogdoches County, Texas 
In 2016, Southern Company acquired PowerSecure, a distributed energy infrastructure technologies company, and AGL Resources (which was renamed Southern Company Gas)  As a result of the AGL Resources merger, Southern Company doubled its customer base, expanded its footprint and broadened the scope of its business by increasing its natural gas presence 

Plant Vogtle
Southern Company subsidiaries operate hydroelectric, gas, coal, and nuclear generation sources to generate approximately 200 terawatt-hours of electricity  In 2009, coal represented 57 percent of the company's output, followed by nuclear (23%) and natural gas (16%)  Renewable hydroelectric power represented 4 percent of Southern's generation  Coal-based generation dropped significantly in 2009 from an average of 70% between 2005 and 2008  As of 2017 Coal-based generation had dropped to 30% In June 2010, the United States Department of Energy awarded an $8 3 billion loan guarantee to facilitate the construction of two new nuclear reactors at Plant Vogtle, near Augusta, Georgia  A Southern Company subsidiary, Georgia Power, owns 45 7% of the current 2,430 MW facility, with co-owners Oglethorpe Power (30%) Municipal Electric Authority of Georgia (22 7%) and the City of Dalton (1 6%)  The plant is operated by Georgia Power  The $14 billion construction project is scheduled to be completed by 2022 and would double the plant's capacity The construction of two 1,154 MW reactors has been hailed by Energy Secretary Steven Chu as "the first new nuclear power plant to break ground in decades"  It is expected to create up to 3,500 jobs during the construction phase, and 800 once operational  However, in March 2017 Westinghouse Electric Company, who were building the plant, filed for Chapter 11 bankruptcy because of $9 billion of losses from its two U S  nuclear construction projects  The U S  government had given $8 3 billion of loan guarantees on the financing of the four nuclear reactors being built in the U S , and it is expected a way forward to completing the plant can be agreed 

Plant Ratcliffe
In September 2013 the EPA introduced new provisions regarding output of carbon emissions in new power facilities  The proposed emission limit for new energy sources will be 1,100lbs of carbon dioxide per megawatt hour of electricity  Preemptively recognizing the need for these changes, Southern Company broke ground on its 21st-century clean coal facility in June 2010  Southern's subsidiary, Mississippi Power will operate the plant  The Kemper County Energy Facility, or Kemper Project, takes advantage of the abundant lignite, or poor quality coal, available in Mississippi  Additionally, it employs Transport Gasifier (TRIG) technology  TRIG technology is built on the idea of dry-feed, non-slag gasifiers, which operate at lower temperatures than other coal gasifiers  This dry-feed is crushed, heated, and circulated in the gasifier, producing a flammable synthetic gas, syngas  Syngas can generate electricity with fewer emissions  Of course, other byproducts are produced, like ammonia and sulphuric acid  These particular products are sold for commercial use The EPA considers the Kemper Coal Project and other planned facilities like it, to be a lifeline for the coal industry in the wake of the new climate change plan  Between 2010 and 2014, approximately 150 coal plants were shut down As of April 2014, the US Department of Energy had invested $270m in this project  Southern Company, and its subsidiary, Mississippi Power anticipate that the Kemper Coal Plant will generate enough energy to serve more than 187,000 customers  Upon opening, the Kemper Coal Project is expected to be capable of stripping out at least 65% of the carbon dioxide, significantly exceeding the EPA's proposed requirement of 40% 

Partnerships
Southern Company works with the US Department of Energy on a variety of projects including transmission and distribution of infrastructure and smart grid initiatives, environmental research programs, and nuclear generation  One of the more significant joint efforts, the DOE's National Carbon Capture Center, is managed by Southern Company and represents national efforts to reduce greenhouse gas emissions from coal-based power generation  At this location, Southern Company has been working with scientists and technology developers from government, industry, and universities who are creating the next generation of carbon capture technologies Along with the DOE, Southern Company has been working with KBR, another technology partner, to perfect its TRIG advanced coal gasification technology  This process of breaking down "dirty coal", or lignite, into its chemical components is not only cleaner, but it is also less expensive and more reliable  This technology is currently being implemented at Southern Company's Kemper County power plant, one of the few new coal facilities working to keep the US coal industry alive  This new facility will be built on a lignite seam, is expected to strip out two-thirds of carbon dioxide emissions, leaving emissions at about the same level as natural gas  The Kemper Coal Plant is expected to fall well under new regulations implemented by the EPA, which limits coal plants to 1,100lbs of carbon dioxide emissions per megawatt hour of electricity In an effort to make this technology more attainable, Southern Company has partnered with China's Shenhua Group to collaborate on further research, development, and deployment of clean coal technologies in the US, China, and around the world  This partnership with Shenhua, who is currently expected to add more than 400,000 megawatts of coal-fired capacity by 2035, could lead to wide deployment of TRIG-equipped power plants across Asia  TRIG technology has the potential to not only assist China with their growing carbon issue, but also enable the country to tap into their own low quality coal In 2009, the U S  Department of Energy granted Southern Company a $165 million Smart Grid Investment Grant to implement a smart grid and to make the grid more reliable  Through matching funds and other investments, the company spent $363 million on the initiative, which it completed in 2014  The upgraded smart grid allows Southern Company the ability to monitor and control its electric infrastructure in real time and respond to problems 

Financial data
Carbon footprint
Southern Company reported Total CO2e emissions (Direct + Indirect) for the twelve months ending 31 December 2020 at 75,300 Kt (-13,100 /-14 8% y-o-y) and aims to reach net zero emissions by 2050 

Political donations
In May 2018, it was reported that Southern Company had donated $1 million to America First Policies, a pro-Donald Trump advocacy group 

Controversies
Environmental impact
Southern Company is the third-largest producer of greenhouse gas emissions in the United States, emitting 86,244,286 metric tons of carbon dioxide equivalent in 2019 In 2005, the company announced it would open a Mercury Research Center at Plant Crist Pensacola, Florida, hoping to find new ways to reduce mercury emissions On April 25, 2006, Alabama Power, a subsidiary of Southern Company, agreed to pay $200M to settle allegations that its coal-fired James H  Miller, Jr  Plant near West Jefferson, Alabama emitted harmful amounts of SO2 and NOx In response to growing public and financial community interest, the company has enacted assorted environmental measures  Southern Company participates in Renew Our Rivers, a volunteer program to remove debris from rivers and other waterways throughout the Southeast, which claims over 11 million pounds of trash removed or recycled in Renew Our Rivers events  The company also manages and operates the National Carbon Capture Center, a focal point of the US Department of Energy's efforts to develop carbon capture and greenhouse gas reduction technologies, under which various projects to test geologic sequestration are in progress at Plant Gorgas in Alabama, Plant Daniel in Mississippi and other company sites  However, critics have argued that CCS seldom works and prolongs the life of fossil fuels 

Climate change denial
Southern Company has a long history of funding climate change denial and has been a "driving force behind climate disinformation," sponsoring campaigns in opposition to climate science, against limiting greenhouse gas emissions, and slowing the transition to renewable energy sources Between 1993 and 2004 Southern Company paid over $62 million to organizations that spread disinformation about climate change  The utility paid for advertising claiming that climate change was not real and made payments to public relations companies, industry groups, law firms and thinktanks to dispute the scientific consensus for climate change and attack legislative solutions  The utility paid $20 million to the trade group Edison Electric Institute, which creates media campaigns to attack proponents of global warming  In the 1990s, Southern Company and the Center for Energy and Economic Development hosted energy workshops broadcast to schoolteachers through the company's satellite network to promote pro-coal messages about climate change and the environment 

Kemper Project controversies
In February 2015, the Mississippi Supreme Court ordered Southern Company's subsidiary Mississippi Power to restore $377 million to South Mississippi ratepayers for rate increases related to the Kemper Project, a "clean" coal plant  These fees were derived from Mississippi's Baseload Act, allowing Mississippi Power to charge ratepayers for powerplants under construction 
In May 2016, Southern Company and its subsidiary Mississippi Power announced they were being investigated by the Securities and Exchange Commission related to overruns at the Kemper Project  The project had been repeatedly delayed and costs increased from $2 88 billion to $6 58 billion  In recorded conversations, at least six engineers from the Kemper Project claimed that delays, cost overruns, safety violations, and shoddy work, were in part due to mismanagement or fraud 
In June 2016, Mississippi Power was sued by Treetop Midstream Services over the cancellation of a contract to receive carbon dioxide from the Kemper Project as part of the carbon capture and storage design  Treetop had contracted to buy carbon dioxide from the Kemper plant and had built a pipeline in preparation to receive the gas  Treetop alleged Mississippi Power had fraudulently and "intentionally misrepresenting and concealing the start date" for the Kemper Project, though Mississippi Power stated the suit was without merit 
The company was also found to have unlawfully fired a whistle-blower who had criticized alleged false statements by company management 

Vogtle nuclear power plant
In June 2021, Georgia Power, a subsidiary of Southern Company, was scrutinized by the Georgia Public Service Commission over the lengthy delays and ballooning costs of its new Vogtle nuclear plant in Burke County, Georgia 

Willie Soon
In February 2015, it was revealed that climate change denier Willie Soon had been paid by Southern Company and several other fossil fuel interest groups  Over the course of 14 years, Soon received a total of $1 25m from Southern Company, Exxon Mobil, the American Petroleum Institute (API) and a foundation run by the Koch brothers, the documents obtained by Greenpeace show  At $410,000, Southern Company was the largest donor  The scientist described his studies to fossil fuel executives as "deliverables", and permitted anonymous pre-publication reviews  Soon advanced the widely discredited theory that changes in solar activity are to blame for climate change, and called into question the severity and extent of climate change in all his studies, never revealing his backers 

See also
Jacob Horton
List of United States electric companies
Electric utility

Notes
External links
Business data for Southern Company: 
DOE guarantee press info
PR Newswire release
Southern Company Media Room
Official website
Forbes Global 2000 Biggest Companies Utility Industry
Passage 3:
TECO Energy
TECO Energy Inc  is an energy-related holding company based in Tampa, Florida, and a subsidiary of Emera Incorporated  TECO Energy has several subsidiaries: Tampa Electric, which provides electricity to the Tampa Bay Area and parts of Central Florida; Peoples Gas Company, which provides natural gas throughout Florida; and TECO Services, which provides IT, HR, legal, facilities, and other services to current and former TECO subsidiaries  Previously the company was in the S&P 500 before it became private due its acquisition by Emera 
TECO Energy businesses include New Mexico Gas Company  TECO's three utilities serve a total of 1 6 million customers in Florida and New Mexico  In 2012, TECO exited its business in Guatemala 

History
Tampa Electric began in 1899 to manage electric trolley systems in the city of Tampa  On September 4, 2015, Emera, a utility holding company based in Halifax, Nova Scotia, Canada, announced the pending acquisition of TECO Energy  That purchase closed on July 1, 2016, and TECO Energy, Inc  became a wholly owned subsidiary of Emera, Inc 

Environmental record
Researchers at the University of Massachusetts Amherst in 2006 identified TECO Energy as the 37th-largest corporate producer of air pollution in the United States in 2002, with roughly 11 million pounds of toxic chemicals released annually into the air  Major pollutants indicated by the study included hydrochloric acid, sulfuric acid, chromium compounds, arsenic compounds, and nickel compounds In 2000, TECO Energy was fined $3 5 million for making changes to emissions producing facilities without installing new updated pollution controls  This led to the switch from coal to natural gas in one of its plants by 2004 and optimization of pollution controls in another  These changes were enacted to drastically cut emissions, notably sulfur dioxide and nitrogen oxide emissions On July 6, 2019 People’s Gas a Division of Tampa Electric Company, caused an explosion of a shopping center in Plantation, Florida known as the Market on University because People’s Gas failed to close and lock a gas line after a customer request dating back to December 2018  The failure to close and lock the gas line is a violation of Federal law and Florida law  Peoples/TECO claims that a computer program cancelled the shutoff order unbeknownst to the utility  TECO/Peoples hid the claimed computer error from state investigators  The computer error caused hundreds of gas line shutoff orders to be cancelled system wide  TECO/Peoples also blame the owner of the shopping center for not capping the gas line when the tenant removed a gas pizza oven  Over 60 lawsuits were filed in response to the explosion many of which remain pending 
In 2017, TECO had an explosion at its Big Bend power plant near Tampa, Florida killing 5 workers who were performing a dangerous procedure water jetting molten slag in a coal fired furnace  The workers were killed because an explosion occurred  TECO experienced the same type of accident 10 years prior and developed a policy to prevent future accidents but failed to train workers on the safety policy  In May 2022, TECO pleaded guilty to violating an OSHA safety regulation requiring a meeting to ensure workers are properly trained that would have prevented the deaths of the 5 workers  In August 2022 TECO was sentenced to a $500,000 fine and 3 years of probation  TECO admitted that it willfully violated an OSHA safety regulation as part of its guilty plea  
On September 28, 2017, TECO announced it was adding 600 MW of solar to its electricity-producing portfolio 

See also
List of power stations in Florida
TECO Line Streetcar (No longer operated by TECO)
Tampa Electric Co  v  Nashville Coal Co 
Passage 4:
Xcel Energy
Xcel Energy Inc  is a U S  regulated electric utility and natural gas delivery company based in Minneapolis, Minnesota, serving more than 3 7 million electric customers and 2 1 million natural gas customers across parts of eight states (Colorado, Minnesota, Wisconsin, Michigan, North Dakota, South Dakota, Texas and New Mexico)  It consists of four operating subsidiaries: Northern States Power-Minnesota, Northern States Power-Wisconsin, Public Service Company of Colorado, and Southwestern Public Service Co In December 2018, Xcel Energy announced it would deliver 100 percent clean, carbon-free electricity by 2050, with an 80 percent carbon reduction by 2035 (from 2005 levels)  This makes Xcel the first major US utility to set such a goal 

History
Xcel Energy was built on three companies: Minneapolis-based Northern States Power Company (NSP), Denver-based Public Service Company of Colorado (PSCo), and Amarillo-based Southwestern Public Service (SPS)  Southwestern Public Service Co  (SPS) dates its origins to 1904 and the Pecos Valley in New Mexico when Maynard Gunsell received an electricity franchise for the city of Roswell, New Mexico and its 2,000 residents  The financial strain of creating this new enterprise soon overwhelmed him and he sold the franchise to W H  Gillenwater, who named his utility the Roswell Electric Light Co  He later sold the company to an investment firm in Cleveland, Ohio, which already owned the Roswell Gas Co Northern States Power Company's timeline begins with the organization of the Washington County Light & Power Co  in 1909  When H  M  Byllesby began building his utility holding company across the Northwestern region of the US, he renamed it the Consumers Power Co  in 1910 and which was renamed the Northern States Power Co  in 1916  While the bulk of NSP's territory grew across central and southern Minnesota (starting from the Twin Cities), it acquired territory in North Dakota (centering on Fargo, Grand Forks, and Minot) and extended southwest into South Dakota (centering on Sioux Falls)  NSP's system also extended east into Wisconsin, but because of utility ownership laws in that state, it was operated as an entity separate from the rest of the company 
Public Service Company of Colorado (PSCo) was formed in 1923 to provide an electric generating station for the Denver area   By 1924, it had acquired most of the electric companies in northern and central Colorado  Originally a subsidiary of Cities Service Company, it became an independent autonomous operation in November 1943   By this time, it served 80 percent of Colorado's gas and electricity needs  As demand for energy continued to grow, so did PSCo   Eventually, the company merged with SPS to form New Century Energies (NCE) in 1995 Northern States Power and Wisconsin Energy Corporation had planned to merge into a new outfit that was to be called Primergy - but in 1997, the merger fell through because of the time it was taking to gain the required approvals from state and federal agencies  After the failed Primergy merger, NSP (both the Minnesota and Wisconsin companies) merged with New Century Energies to form Xcel Energy   In 2005, Xcel sold Cheyenne Light, Fuel and Power to Black Hills Corporation   Cheyenne Light, Fuel and Power had been a subsidiary of PSCo since the 1920s, and had become an operating company of NCE after the merger with SPS 
In December 2018, Xcel Energy became the first major US utility to pledge to go carbon-free, aiming for 80% carbon reduction by 2030, and 100% reduction by 2050 Utility industry magazine Utility Dive awarded Xcel Energy its 2018 "Utility of the Year" award for its plans for add 12 wind farms, its project with Google to develop new ways for customers to personalize energy management, and its plan to retire 50 percent of its coal-powered capacity by 2026 (and replacing it with a combination of renewable energy, efficiency, and natural gas) On May 20, 2019, Xcel Energy announced its intent to close all of its remaining coal-fired plants in Minnesota by 2030 while compensating by increasing solar production capacity by 1,400%  It also declared its plans to continue operating its Monticello nuclear plant near Monticello, Minnesota until at least 2040 On March 16, 2023, Xcel Energy announced that a significant unplanned release of radioactive water from its Monticello nuclear power plant took place on November 21, 2022, which was reported only to state and federal authorities but was concealed from the public until now  Xcel estimated the leak to be 400 thousand gallons of contaminated water containing radioactive tritium  The leak occurred in a water pipe that runs between two buildings 

Generation portfolio
Across Xcel Energy's eight-state service area, 49% of the power provided in 2021 came from carbon-free sources: biomass, hydroelectric and nuclear plants, solar panels and wind turbines Xcel Energy currently has 13 coal plants with a capacity of 7,697 MW  Seven of those plants are operated in Colorado  Xcel Energy owns and operates three wind farms  In October 2011, Xcel Energy set a world record for electricity from wind power, with an hourly penetration of 55 6% of production from wind Xcel Energy generates over 500 megawatts of hydroelectric power from 27 plants in Wisconsin, Minnesota, and Colorado  This accounts for only four percent of their electricity generation  They also purchase large amounts of hydro-generated electricity from Manitoba Hydro 

Biomass electricity comes from organic fuel sources  Xcel Energy has contracts for about 110 megawatts of electricity from biomass generators  Two in northern Minnesota are fueled by forest harvest residue, such as treetops and limbs  A third facility, brought on line in 2007 in western Minnesota, generates power using turkey litter Xcel Energy's Bay Front plant in Ashland, Wisconsin, is a three-unit generating station that has become a model for the creative use of fuels: coal, waste wood, railroad ties, discarded tires, natural gas, and petroleum coke   Two of the three Bay Front operating units already use biomass as their primary fuel   Xcel Energy recently proposed a plan to install biomass gasification technology at Bay Front  The waste-to-energy facilities use waste that would otherwise end up in landfills  The Wisconsin waste-to-energy plant burns wood waste in combination with refuse-derived fuel (RDF) Xcel Energy owns and operates two nuclear power plants: 

Monticello Nuclear Generating Plant near Monticello, Minnesota
Prairie Island Nuclear Generating Plant near Red Wing, Minnesotaand stores the spent fuel from these nuclear plants on site in independent spent fuel storage installations  (ISFSIs) 

System information and transmission
Xcel Energy operates the fourth largest transmission system in the United States, spanning 10 states  In 2011, Xcel Energy's transmission system was worth $3 3 billion The transmission system is operated on a non-discriminatory basis under the open access requirements of the Federal Government  This means that all wholesale buyers and sellers of electricity can use the transmission system under the same terms and conditions used to serve Xcel Energy's own retail customers   The transmission lines are utilized to carry 115,000 volts, 230,000 volts, and 345,000 volts   There is also a 500,000 volt transmission line that runs from the Dorsey Substation outside of Winnipeg, Manitoba in Canada to the Chisago Substation located in Chisago County just north of St  Paul, Minnesota 

Grid security
In 2017, Xcel Energy partnered with the Financial Services Information Sharing and Analysis Center to create a new "threat information sharing community" intended to share cyber and physical security intelligence with the energy sector  The new community is called the Energy Analytic Security Exchange (EASE)  It is run by the FS-ISAC Sector Services team; FS-ISAC is an organization that gathers cyber and physical risk intelligence for the financial services industry  Additionally, the North American Electric Reliability Council (NERC) manages the Electricity Information Sharing and Analysis Center, which is another resource that the energy sector uses to gather threat intelligence 

Advanced Grid in Colorado
In 2016, Xcel Energy announced the Advanced Grid Intelligence and Security (AGIS) initiative, a long-term effort related to power reliability, distributed generation, and information sharing with customers  Through the initiative, Xcel would build an "intelligent grid" in Colorado in order to improve grid security  The company filed a request for permission with the Colorado Public Utilities Commission for the program, which would cost $500 million 

Programs
Since 1998, Xcel Energy's Windsource program has allowed customers to designate that part or all of their electricity comes from a renewable energy source  In 2015, about 96,000 people were enrolled in Windsource  In 2011, more than 2 3 million electric and 261,800 natural gas customers took part in Xcel Energy's energy efficiency programs for homes and businesses Xcel Energy also offers customers incentives to install solar panels  At the end of 2011, more than 10,600 photovoltaic systems had been installed, with a capacity of about 121 megawatts (DC)  In early 2011, Xcel Energy suspended the solar rebate program before reaching a settlement a month later with representatives of solar power companies to restore the solar incentive program until it is fully reviewed by the Public Utilities Commission 

Controversies
On August 1, 2002, Xcel Energy Inc  was sued because of engaging in "round-trip" energy trades that provided no economic benefit for the company, and because the company lacked the necessary internal controls to adequately monitor the trading of its power  Xcel paid $80,000,000 in a settlement The Cabin Creek Fire occurred on October 2, 2007, at Xcel Energy's Hydropower Generation plant in Georgetown, Colorado  On June 1, 2011, Federal prosecutors opened their charges that Xcel Energy was criminally liable for the deaths of the five RPI workers  On June 28, the jury found Xcel Energy not guilty  On December 19, 2011, RPI Coating pleaded guilty to workplace safety violations and paid $1 55 million in a cash settlement  The company took responsibility for the deaths of five workers and the injuries to three  The U S  Chemical Safety and Hazard Investigation Board conducted an investigation of the incident  Its report can be found on the CSB website  It is considered one of the worst unmitigated incidents to occur in a permit-required confined space The parent company to Xcel Energy, and later Xcel Energy itself have operated the Prairie Island Nuclear Power Plant since 1973  Over that time, nuclear waste produced by the power plant has been stored adjacent to the Prairie Island Indian Community  The homes of some members of the community are within 600 yards of the nuclear waste containment site and, sitting within the banks of the Mississippi River, the island is very vulnerable to seasonal flooding  While in 1991, the Minnesota Public Utilities Commission capped the storage of nuclear waste on the island to 17 casks, the legislature has since permitted this number to increase  Environmentalists and members of the Prairie Island Indian Community have been working since 1994 to have this nuclear waste transported away from their reservation due to the combined risk of the temporary design of the storage facility, unpredictable flooding and single evacuation road in the event nuclear waste is released from containment 

See also
Plant X, Lamb County, Texas
Passage 5:
Electric Bond and Share Company
The Electric Bond and Share Company (Ebasco) was a United States electric utility holding company organized by General Electric  It was forced to divest its holding companies and reorganize due to the passage of the Public Utility Holding Company Act of 1935  Following the passage of the Act, the U S  Securities and Exchange Commission (SEC) selected the largest of the U S  holding companies, Ebasco to be the test case of the law before the U S  Supreme Court  The court case known as Securities and Exchange Commission v  Electric Bond and Share company was settled in favor of the SEC on March 28, 1938  It took twenty-five years of legal action by  the SEC to break up Ebasco and the other major U S  electric holding companies until they conformed with the 1935 act  It was allowed to retain control of its foreign electric power holding company known as the American & Foreign Power Company (A&FP)  After its reorganization, it became an investment company, but soon turned into a major designer and engineer of both fossil fuel and nuclear power electric generation facilities  Its involvement in the 1983 financial collapse of the Washington Public Power Supply System's five nuclear reactors led to Ebasco's demise because of the suspension of nuclear power orders and lawsuits that included numerous asbestos claims  The U S  nuclear industry stopped all construction of new facilities following the 1979 nuclear meltdown at Three Mile Island, going into decline because of radiation safety concerns and major construction cost overruns 

History
The Electric Bond and Share Group was organized in 1905 as a holding company for electric utility company securities by General Electric using its employees' retirement investment fund  Morgan used his control of General Electric and his position as the country's most powerful financier to set in motion a plan to monopolize the entire country's electric industry via the Electric Bond and Share Group  Until his death in 1913, Morgan was opposed to any form of government regulation  His firing of Samuel Insull resulted with Insull moving to Chicago, where he organized the second-largest holding company in the country, the Middle West Utilities Company or what is known today as Exelon  Insull would actively promote the idea of a regulated monopoly because of the high cost of electrical infrastructure  About the same time as Teddy Roosevelt's trust busting campaign against Morgan, Rockefeller and other elites was gaining national attention, the National Civic Federation (NCF) was formed   It carried out extensive investigations and debates among prominent business men and organized labor over the issue of public vs  private ownership of electric power  Insull's public support for regulation helped popularize NCF's model legislation that quickly spread nationwide after the state of New York adopted its own variation  Morgan's son J  P  Morgan Jr  carried on with the House of Morgan, including his father's goal of a national electric monopoly but was up against the reformist progressive era 
By 1925, General Electric's Electric Bond & Share Group was the largest owner of U S  and foreign electric companies holding over 10% of the country's companies as subsidiaries organized into five major holding companies   General Electric made a purely symbolic gesture to reduce growing public anger by divesting control of the company leaving Morgan still in financial control  The Commonwealth & Southern Corporation, which owned several utility operating companies in the Midwest and the South, some of which became part of the Southern Company, and the reorganized Electric Bond And Share Company (EBASCo) were both part of J  P Morgan's syndicate via his J P  Morgan & Co  In 1926, its headquarters in New York City had over 1,000 employees, and controlled companies in 33 states worth $1 25 billion As public concern continued to mount by ratepayers of private electric power companies, the Federal Trade Commission carried out extensive investigations between 1928 and 1935  The commission's 48,000-page report included entire volumes for each of the country's major utility companies  The FTC valued EBASCo and its five holding companies at $3 5 billion, along with major investments in dozens of other major U S  companies  Within the five main holding companies were 121 U S  subsidiaries, along with a foreign holding company that operated in 16 countries and had 70 subsidies 
Because he was a strong proponent of public power, Franklin D  Roosevelt used the collapse of Samuel Insull's Middle West Utilities electric empire in June 1932 as one of his most important election campaign issues  The failed assassination attempt on his life in February 1933 later became part of U S  Marine Corps General Smedley Butler's claim of a Business Plot against Roosevelt by J  P  Morgan  On Roosevelt's first day in office, following his inauguration, he ordered the closure of the nation's banks, known as the bank holiday of 1933  In a joint session of the House and Senate, he pushed through the Emergency Banking Act along with Executive Order 6102 that blocked the hoarding of gold and stopped the major New York banks from taking gold supplies out of the country   Roosevelt then selected Ferdinand Pecora to investigate Morgan and the country's other major banks
Context 3: Passage 1:
Band-e Amir National Park
Band-e Amir National Park (Persian: بند امیر) Afghanistan established its first national park on April 22, 2009, to promote and protect the natural beauty of a series of intensely blue lakes created by natural dams high in the Hindu Kush  Band-e-Amir is a chain of six lakes in the mountainous desert of central Afghanistan  The lakes formed from mineral-rich water that seeped out of faults and cracks in the rocky landscape  Over time, the water deposited layers of hardened mineral (travertine) that built up into walls that now contain the water  According to the Wildlife Conservation Society, who helped the Afghan government set up the park, Band-e-Amir is one of the few travertine systems in the world They were created by the carbon dioxide rich water oozing out of the faults and fractures to deposit calcium carbonate precipitate in the form of travertine walls that today store the water of these lakes  Band-e Amir is one of the few rare natural lakes in the world which are created by travertine systems  The site of Band-e Amir has been described as Afghanistan's Grand Canyon, and draws thousands of tourists a year  The river is part of the system of the Balkh River 

History
The name Band-e Amir literally means "the Ruler's Dam" which is believed by some to be a reference to Ali, the fourth Caliph of the Muslims  The area is dominated by ethnic Hazaras, who are estimated to make up about 40 percent of Afghanistan's population In her 1970 guide to Afghanistan, Nancy Dupree wrote that a full description about Band-e Amir would "rob the uninitiated of the wonder and amazement it produces on all who gaze upon it"  Parts of the 1975 Bollywood film Dharmatma, with Feroz Khan and Hema Malini, were filmed at the Band-e Amir National Park In 2004, Band-e Amir was submitted for recognition as a World Heritage site  Efforts to make Band-e Amir a national park started in the 1970s, but were then put on hold due to the wars  In April 2009, Band-e Amir was finally declared Afghanistan's first national park  As of 2013, about 6,000 local tourists visit the Band-e Amir National Park every year  The area is protected by a small number of park rangers 

Geography
Band-e Amir is situated at approximately 75 km to the north-west of the ancient city of Bamyan, close to the town of Yakawlang  Together with Bamyan Valley, they are the heart of Afghanistan's tourism, attracting thousands of tourists every year and from every corner of the world  The Band-e Amir lakes are primarily a late spring and summertime tourism destination, as the high elevation central Hazarajat region of Afghanistan is extremely cold in winter, with temperatures reaching as low as −20 °C (−4 0 °F)  The six constituent lakes of Band-e Amir are:

Band-e Gholaman (Lake of the slaves)
Band-e Qambar (Lake of Caliph Ali's slave)
Band-e Haibat (Lake of grandiose)
Band-e Panir (Lake of cheese)
Band-e Pudina (Lake of wild mint)
Band-e Zulfiqar (Lake of the sword of Ali)The white travertine dams created by fault lines, which are prevalent in the Band-e Amir Valley, form the barriers between the lakes  Band-e Haibat is the biggest and the deepest of the six, with an average depth of approximately 150 metres, as estimated by the Provincial Reconstruction Team diving team from New Zealand  Another comparable lake is Band-e Azhdahar (The Dragon), located a few kilometres southeast of the town of Bamyan, which has also been created as a result of carbon dioxide rich water oozing out of the faults underground and depositing calcium carbonate precipitate to form the travertine walls of Band-e Amir 

Climate
High in the Hindu Kush at approximately 2,900 metres (9,500 ft) above sea level, the national park has a subarctic climate (Dsc) closely bordering on a warm-summer humid continental climate (Dsb)  The climate is extremely severe and the lakes freezing over in winter 

Current status
After the formal establishment of the park in 2009, a park office with a park warden and a group of rangers was installed to manage the conservation and protection of park natural resources  Wildlife Conservation Society (WCS) is the only non-government organization with an office in the park  WCS supports park staff and works with the local community to promote conservation and sustainable use of natural resources  Ecotourism is expected to decrease local economic dependency on the park's natural resources  Tourists visit Band-e-Amir primarily in the summer months when the weather is warm  A poor local economy and limited outside investment have hampered efforts to attract winter tourism



ground_truth: Ribosomes

prompt_front: Answer the question based on the given passages. Only give me the answer and do not output any other words.

Question: Which utility holding company did Alfred A. Marcus work as a consultant?

The following are given passages.
Context 2:  Both Pecora and the Federal Trade Commission investigations  exposed the fact that the electric industry was the most capital intensive industry  The May 24th, 1933 Pecora hearings rocked the country, focusing on J P  Morgan and his financial empire, whose top lieutenants paid no taxes  In his 1939 book Wall Street Under Oath: The Story of Our Modern Money Changers, Ferdinand Pecora stated that "Undoubtedly, this small group of highly placed financiers, controlling the very springs of economic activity, holds more real power than any similar group in the United States "The 1933 Pecora Commission hearings identified the National City Company, known today as Citibank, as the location where Morgan conducted EBASCo's investment operations, which played a prominent role in the passage of the Glass–Steagall legislation  The Pecaro investigation along with the findings from the seven-year Federal Trade Commission investigation into electric holding companies nationwide led to the passage of the Public Utility Holding Company Act of 1935  which some historians say was "the fiercest congressional battle in history "  Following the act's passage, Ebasco sued the United States government claiming it was unconstitutional, but lost the case before the Supreme Court in 1938  Wendell Willkie, who was the president of one of J P  Morgan and Ebasco's biggest investments, known as the Southern Company, ran against Franklin D  Roosevelt in the 1940 presidential race, but lost 

EBASCo, known on Wall Street as (EBS) was included in the Dow Jones Utility Average from  1938 to 1947 

Securities and Exchange Commission breakup of EBASCo
Following the passage of the Public Utility Holding Company Act of 1935, the U S  Securities and Exchange Commission (SEC) oversaw the closure, re-organization or divestment of EBASCo's holding companies except for its American & Foreign Power Co , making annual reports on its monumental legal breakup case between 1936 and 1961  The act was used to break up the country's electric industry into regions confined by state boundaries so that state agencies could properly regulate each company  Each year, the SEC reported on the compliance status of the industry   As of 1949, 210 holding companies affecting 918 of the country's electric companies had come under the SEC's legal jurisdiction and procedures, with 46 holding companies still active   In its 1949 annual report, the SEC documented the history of their order for EBASCo to break up its five major holding companies' combined assets worth $3 5 billion 
In 1940, congressional investigations of brokerage firms, insurance companies and their relationship to the electric industry exposed that Middle South Utilities, the Southern Group and Ebasco were all financed by Morgan Stanley, with Wall Street having financial influence over nearly 80% of the country's electric industry 
Following the passage of the 1935 Act, Ebasco went into the U S  court system in an attempt overturn the act but failed (see external links for major court cases)  Ebasco was then required to register its holding companies and comply with SEC orders  On August 23, 1941, its holding company known as the National Power & Light Co  was ordered to break up its 27 subsidiaries  On March 22, 1949, the SEC signed off on the final breakup of National that included major holdings in Pennsylvania PPL Corporation, the Carolinas and Alabama (see subsidiary list) 
On August 22, 1942, the SEC ordered the breakup of Ebasco's holding companies known as American Power & Light Corp  that included 35 subsidiaries and the Electric Power & Light Corporation with its 24 subsidiaries  American appealed the ruling but lost before the U S  Supreme Court on November 25, 1946  As of 1949, all but one of American's subsidiaries were in compliance  Electric Power and its sub-holding company United Gas Corporation finally agreed to its breakup on March 2, 1949  Electric Power was then re-organized as Middle South Utilities Inc  and is known today as Entergy 
In 1939, proceedings before the SEC were initiated to break up EBASCo's American Gas & Electric Company  On December 28, 1945, the agency agreed to allow it to retain control of its central region of subsidiaries in Indiana, Kentucky, Michigan, Ohio, Tennessee, Virginia, and West Virginia, if it let go of its companies in Pennsylvania and New Jersey  In 1946, it attempted to acquire the Continental Gas & Electric Corp  but was denied   American Gas & Electric Company was finally spun off in 1958 to become American Electric Power (AEP) 
As part of a national campaign to deregulate the electric industry, the Bush administration and Congress passed the Energy Policy Act of 2005 that repealed the 1935 Public Utility Holding Company Act 

EBASCo holding companies prior to 1935
The following EBASCo holding companies, which includes some of its subsidiaries came under enforcement by the Securities and Exchange Commission with the passage of the Public Utilities Holding Company Act of 1935 

American Gas & Electric Company
Incorporated in 1906, and controlled by EBASCo , American Gas & Electric Company was finally spun off in 1958 and became American Electric Power  AEP currently serves over 5 million electricity customers in eleven states  It is currently the 6th largest gas & electric company in the United States  Check the reference here for a recent list of AEP's  subsidiaries 
Appalachian Electric Power Co  - Known today as Appalachian Power
Ohio Power Co  - Known today as AEP Ohio
Indiana & Michigan Electric Co  - known today as Indiana Michigan Power
The Scranton Electric Co  was sold to PPL Corporation in 1956
Atlantic City Elec  Co  - Is currently a subsidiary of Exelon
Ky  & W  Va  Power Co  - known today as Kentucky Power
Wheeling Electric Co  - is currently a subsidiary of AEP
Indiana General Service Co 
Kingsport Utilities, Inc  - known today as Kingsport Power Company

American Power & Light Company
American Power & Light had over 35 subsidiaries prior to 1935   In 1942, the Securities and Exchange Commission ordered the holding company to be broken up, which was completed by 1951  Many of these companies are still in existence today  

Citizens Power & Light Co , Council Bluffs, Iowa 
Central Arizona Light & Power Co , Phoenix, Arizona, merged with Arizona Edison in 1952 to form Arizona Public Service
Florida Power & Light Co , Miami, Florida  It is a subsidiary of NextEra Energy Resources
Fort Worth Power & Light Co , Fort Worth, Texas  Became part of TU Electric in 1984 
Helena Gas & Electric Co , Helena, Montana 
Kansas Gas & Electric Co , general office, Wichita, Kansas, merged with Kansas Power and Light of Topeka in 1992 to form Westar Energy
Minnesota Power & Light Co , general office, Duluth, Minnesota 
Missoula Public Service Co , Missoula, Montana, acquired by Montana Power Company in 1929
Montana Power Company, Butte, Montana  is still operating today 
Nebraska Power Co , Omaha, Nebraska 
Northern Power Co , Superior, Wisconsin 
Northwestern Electric Co , Portland, Oregon 
Pacific Power & Light Co , Portland, Oregon  is known today as PacifiCorp and owned by Berkshire Hathaway Energy 
Portland Gas & Coke Co , Portland, Oregon 
St  Augustine Co , St  Augustine, Florida 
Superior Water, Light & Power Co , Superior, Wisconsin 
Texas Electric Service Co , Dallas, Texas  Became part of TU Electric in 1984 
Texas Power & Light Co , Dallas, Texas  Became part of TU Electric in 1984 
Texas Public Utilities Corp , Dallas, Texas  Became part of TU Electric 
Washington Water Power Co  (The), group, Spokane, Washington is known today as Avista 

Electric Power & Light Corporation
Incorporated in 1925 as a holding company for various Electric Bond & Shares Co  subsidiaries  The SEC ordered it sold off, a process that was completed in 1949, when it was renamed as Mid South Utilities, Inc  Today, it is known as Entergy 

Arkansas Power & Light Co , Little Rock, Arkansas 
Dallas Power & Light Cd  Dallas, Texas 
Idaho Power Co , Boise, Idaho 
Louisiana Gas & Fuel Co , Shreveport, Louisiana 
Louisiana Power & Light Co , New Orleans, Louisiana 
Mississippi Central Power Co , Jackson, Mississippi 
Mississippi Power & Light Co , Jackson, Mississippi 
Nevada Power Co , Boise, Idaho 
New Orleans Public Service Inc , New Orleans, Louisiana 
Salmon River Power & Light Co , Boise, Idaho 
Utah Light & Traction Co , Salt Lake City, Utah 
Utah Power & Light Co , Salt Lake City, Utah 
Western Colorado Power Co , Durango, Colorado 

National Power & Light Company
Incorporated 1925 as new holding company for various Electric Bond & Shares Co  subsidiaries  As part of the SEC's order, National Power was combined with Lehigh Power Securities with most of its other companies broken up   Today, National Power is known today as PPL Corporation

Birmingham Electric Co , Birmingham, Alabama 
Carolina Power & Light Co , Raleigh, North Carolina
Holston River Electric Corporation, Rogersville, Tennessee 
Houston Lighting & Power Co , Houston, Texas 
Knoxville Power & Light Co , Knoxville, Tennessee 
Memphis Power & Light Co , Memphis, Tennessee 
South Texas Utilities Co , Houston, Texas 
Tennessee Public Service Co , Newport, Tennessee 
West Tennessee Power & Light Co , Jackson, Tennessee 

Lehigh Power Securities Corporation
The Lehigh Power Securities Company was merged with EBASCo's National Power & Light Company 

Pennsylvania Power & Light Co , Allentown, Pennsylvania  - PPL Corporation today 
Lancaster Group, Edison Electric Co , Lancaster,  Pennsylvania 
Transit Group, Lehigh Valley Transit Co , Allentown, Pennsylvania 

American & Foreign Power Company
Following the failed merger negotiations with Canada's Royal Securities Corporation, American & Foreign Power Co  was created as a wholly owned EBASCo holding company in 1923 that had the goal of owning electric companies worldwide  With its agenda of enforcing patents, General Electric (GE) had been buying up electric stocks worldwide, but also started taking control of companies via its equipment sales and other services formerly performed by its holding company, the Electric Bond and Share Group   In 1917, Electric Bond and Share Group's first major foreign electric acquisition, at the request of the U S  government, to take control of electric production for two cities near the Panama Canal as a counter strategy against nearby German interests    In 1920, Electric Bond obtained control of Guatemalan electric facilities that the U S  government had seized from Germany during the war    This was followed in 1922 by a dramatic burst of purchasing across central and South America that was followed the next year by the formation of the American & Foreign Power Company 
In 1925, GE would dispose of its Ebasco stocks because of negative public opinion, however GE's chairman continued to sit on American & Foreign Power's board of directors while its founding president Sydney Z  Mitchell also stayed as president   In 1929 American & Foreign Power claimed to have worldwide assets of $750 million  By 1931 the holding company was supplying power to just under 1,000 communities around the world  Following the passage of the Public Utility Holding Company Act of 1935, Ebasco was allowed to retain control of American & Foreign Power Company as the law only applied to U S  based electric utility companies 
Electric development in Cuba is of unique historic concern   Following the Spanish–American War in 1898 the country was forced into an exclusive relationship with the United States   The U  S  allowed Cuba to be independent, but required it to operate under the Platt Amendment of 1901, turning it into an exclusive U S  plantation colony with its sugar exports only allowed to be marketed in the U S    Business interests deployed a combination of Scientific racism and Scientific management practices that left the country exclusively in the hands of American companies 
It started in 1922 with GE's representative, Henry Catlin purchasing General Gerardo Machado's electric company and then donating $500,000 to the general's successful bid to become Cuba's president in 1924  GE would spend $100 million to purchase control of Cuba's entire electric infrastructure    This led to 40 years of societal stresses, years of military dictatorships, the infamous U S  Mafia operations in Havana and the Cuban Revolution which allowed Cuba to  nationalize American & Foreign Power's control of the country's electric utilities 
American & Foreign Power Company also had operations in the following countries:

Argentina - 100 different electric companies
Brazil
Canada - British Columbia Power Corporation
Chile - all major electric utilities 
China - 1929 Shanghai Power Company purchased for $32 million
Colombia
Costa Rica
Cuba - Cuba Electric Co  taken public by Cuba in 1960
Ecuador
Guatemala
India
Italy - Italian Superpower Corporation
Japan -  Two Companies
Mexico
Panama - 1917 purchased two companies at the request of the U S  around the Panama Canal
Venezuela

Dixon-Yates Affair
With the election of President Eisenhower in 1952 as the first republican to hold office in 20 years, a major policy shift called "no new starts" began   All federal water and power projects that had been closely tied to local, state or federal ownership were ended   The scale of this policy shift was exposed with the Dixon-Yates affair, identifying the plan's source as the Pacific Gas & Electric Company   PG&E was known for getting conservative politicians to kill all funding to the massive Central Valley Project's grid, forcing the U S  Bureau of Reclamation to rely on the company to deliver the electricity  As a result, cooperatives in communities across northern California that were set up to get the low cost surplus power collapsed 
In 1954, President Eisenhower ordered the Atomic Energy Commission to buy 600,000 kilowatts of electricity for its Oak Ridge National Laboratory from two private electric companies rather than purchase power from the Tennessee Valley Authority in what is known as the Dixon-Yates contract   The attempt to bypass TVA's public power system next door to Oak Ridge stirred a national scandal following the testimony of James D Stietenroth, who was the secretary-treasurer of Mississippi Power Company who said that Middle South Utilities was still dominated by Ebasco Services  Stietenroth was fired the next day   Following the release of a secret report by industry insiders meant only for the president's eyes, Eisenhower was forced to cancel the contract on July 11, 1955 
In 1961, after 26 years of legal cases, Electric Bond and Share had complied with the SEC's orders and was no longer listed as an electric power holding company  In 1967, Electric Bond and Share merged with its former holding company, the American & Foreign Power Co  and was renamed Ebasco Industries the following year   Ebasco Industries held onto Ebasco Services Inc  as a subsidiary 

Ebasco Services
On November 27, 1935, the Electric Bond & Share Company setup Ebasco Services to manage its holding company empire, the day after the SEC filed a lawsuit ordering the company to register as a holding company as required by the passage of the Public Utility Company Holding Company Act  According to the asbestos legal case of FENICLE v  BOISE CASCADE COMPANY, Boise Cascade purchased control of Ebasco Industries and its subsidiary Ebasco Services in 1969  The Plaintiff's suit was countered by a legal maneuver called Piercing the corporate veil  In 1973 Halliburton purchased Ebasco Services from Boise Cascade, but the Justice Department reversed the sale over concerns that it gave Halliburton control over too much of the industry's engineering expertise By the mid-1970s, Ebasco had stepped beyond its 1961 filing with the SEC, claiming its intention of becoming an investment company  It was now actively involved with the construction of nuclear and fossil fuel power facilities  In 1976, according to Encyclopedia com a Texas oil company named  Ensearch acquired Ebasco  Ensearch was originally known as Texas Power & Light Co  and had been one of Ebasco's original subsidiaries prior to 1935, that is now TXU Energy  By 1980, EBASCO had three divisions: A/E Ebasco Services, Ebasco Environmental, which provided environmental services, and Ebasco Engineering and Construction  On November 16, 1982, according to a filing made with the Texas Secretary of state, Ebasco Engineering and Construction filed as a foreign for-profit company  Ebasco Environmental was sold to Foster Wheeler, Inc , becoming Foster Wheeler Environmental 
Ebasco had become one of the major US architect-engineers, coordinating the design of many nuclear power plants both in the US and abroad  On May 22, 1956, Ebasco's subsidiary, American & Foreign Power Co  announced plans to build two nuclear power facilities in Latin America, very likely in Cuba since they held 100% of the country's electric production  Other major nuclear construction plans included the Fukushima Daiichi Nuclear Power Plant (units 1, 2 and 6)  It also had the original contract to design and build the Bataan Nuclear station in the Philippines, but was replaced by Westinghouse  Ebasco's involvement with the financial collapse of the Washington Public Power Supply System's (WPPSS) massive five nuclear reactors  led to a lawsuit against the company in 1992 over asbestos contamination Raytheon acquired Ebasco in 1994 and was known as Raytheon Ebasco Overseas Ltd  At this time, Ebasco was known to have subsidiaries in 11 foreign countries  The Raytheon subsidiary, Raytheon Engineers & Constructors that owned Ebasco Services was later sold to Morrison Knudsen Corporation where the combined company was named the Washington Group International, Inc , a firm with more than $5 billion in annual revenues and a backlog of some $6 6 billion, marking it one of the largest in the engineering and construction industry at that time with more than 38,000 employees at work in more than 40 countries  Washington Group International, which filed for Chapter 11 bankruptcy in 2001  At the time of the filing, there were four known Ebasco entities involved in the bankruptcy that included the Delaware-based Ebasco International Corporation   The Washington Group's headquarters were at the World Trade Center in 2001  Ebasco had been at the WTC since 1980 and at one point was its largest tenant with over 2,000 employees, leasing over 600,000 sq  ft  There were less than 20 employees of the 180 still at the World Trade Center on 911  In 2007 Washington Group was purchased by URS Corporation, which was purchased by AECOM in 2014 that is now one of the largest engineering firms in the world 
Following the 2007 takeover of TXU Corp , which included plans to construct two new next generation nuclear power stations at Commanche Peak, the company eventually ran into further financial difficulties and filed for bankruptcy in 2014   On February 27, 2018, Energy Futures Holdings (EFH), formerly known as TXU Corp , which was one of Ebasco's pre-1935 subsidiaries came out of bankruptcy reorganization as TXU Energy  EFH had a subsidiary known as EEC Holdings which owned Ebasco Canada Ltd  that was incorporated in Delaware  Ebasco Canada was shut down on April 29, 2014, as part of the EFH bankruptcy process According to a 2015 Sun Sentinel news story, Ebasco's American and Foreign Power Company is owned by another company - Office Depot  The article says that when Boise Cascade sold off Ebasco Services to Raytheon, it held onto American & Foreign Power Co 's foreign investments   Boise Cascade purchased OfficeMax and took its name in 2003   According to the article, OfficeMax was then purchased by Office Depot in 2013, and was proposing to merge with Staples in 2015  One of the subsidiaries of American & Foreign Power Co   was the former Cuban Power Co  that has filed a $267 5 million claim against Cuba with the Foreign Claims Settlement Commission that still has thousands of investors holding stock in the nationalized company  The Office Depot and Staples merger was abandoned in 2016 after a judge blocked the plan In 2016, The Indian subsidiary Raytheon Ebasco Overseas Ltd  appeared in an Indian court over Tax problems Meanwhile, the Dutch registered CT Corporation is listing itself as the agent for Ebasco in 43 states and the District of Columbia 
See Boise Cascade v  United States for more background on the activities of Ebasco Industries In addition, The law firm of Reid and Priest used to be part of the army of lawyers that failed to stop Ebasco from being dismantled   It became part of Reid, Priest and Thelen LLP which also just dissolved 
Today there is a company Named Ebasco Trading Co  listed in Dubai  Its unknown what its relationship is to the original company 
See Ebasco Services for its whistle-blowing problems  See External links for a list of major legal cases Ebasco has been involved in   Note that this list is no where exhaustive since the company was constantly caught up in legal cases against its own employees, insurance companies and regulatory oversight agencies nationwide 
The Public Utilities Holding Company Act of 1935 was repealed by the Energy Policy Act of 2005
Passage 6:
Spire Inc
Spire Inc  (NYSE: SR) is a regional public utility holding company based in St  Louis, Missouri, providing natural gas service through its regulated core utility operations while engaging in non-regulated activities that provide business opportunities  Its primary subsidiary Laclede Gas Company is the largest natural gas distribution utility in Missouri, serving approximately 631,000 residential, commercial and industrial customers in the City of St  Louis and ten counties in eastern Missouri   Its corporate headquarters is located in the 700 Market building in downtown St  Louis 
On April 29, 2016, the company began trading on the New York Stock Exchange under the symbol SR   It had previously been known as the Laclede Group, trading under the symbol LG 

History
Laclede Gas Company was one of the original 12 industrial companies that made up the Dow Jones Industrial Average but was removed in 1899  On December 7, 2009, executives from The Laclede Group visited the New York Stock Exchange (NYSE) to ring the closing bell and commemorate the company’s 120th anniversary of trading on the exchange  The Company first listed its stock on November 14, 1889, making it the 8th-oldest listed stock on the NYSE 
On February 1, 2012, Laclede hired its first female CEO, Suzanne Sitherwood  Sitherwood earned a bachelor of science degree in industrial engineering technology from the Southern College of Technology and an MBA from Brenau University In 2013, The Laclede Group acquired Missouri Gas Energy from Southern Union Company, expanding their Missouri holdings to include Kansas City 
In 2014 Laclede acquired Alabama Gas Corporation (Alagasco), which serves the Greater Birmingham, East Lauderdale County, Gadsden, Jasper, Anniston-Oxford, Greater Tuscaloosa, Greater Montgomery, Opelika-Auburn, Tuskegee, Selma, and many Black Belt communities as Spire Alabama Inc 
On April 28, 2016, The Laclede Group shareholders approved renaming the company to Spire   Later in 2016, Spire acquired Energy South, Inc from Sempra U S  Gas & Power, the parent company of Mobile Gas and Willmut Gas   Mobile Gas operates in Mobile, Alabama as Spire Gulf Coast Inc  while Willmut gas operates in Hattiesburg, Mississippi as Spire Mississippi Inc  

See also
Laclede Gas Company - Subsidiary of the Laclede Group
Laclede Gas Building
Passage 7:
North American Company
The North American Company was a holding company incorporated in New Jersey on June 14, 1890, and controlled by Henry Villard, to succeed to the assets and property of the Oregon and Transcontinental Company  It owned public utilities and public transport companies and was broken up in 1946, largely to comply with the Public Utility Holding Company Act of 1935 
Its headquarters were at 60 Broadway in Manhattan 

Holdings
In 1889 New Jersey passed legislation to facilitate the control of other companies by another corporation with a goal of encouraging trusts to convert into holding companies and relocate to that state  To take advantage of these expanded corporate powers, in 1890 Oregon and Transcontinental, which was an Oregon corporation, re-incorporated as a holding company in New Jersey and became the North American Company By 1940, North American was a US$2 3 billion holding company directly and indirectly heading up  80 companies  It controlled ten major direct subsidiaries in eight of which it owned at least 79%  Three of the ten were major holding companies:
Union Electric Company of St  Louis, Missouri
Washington Railway and Electric Company
North American Light and Power CompanyFour of the ten direct subsidiaries were operating companies:

Cleveland Electric Illuminating Company
Pacific Gas and Electric
Detroit Edison Company
Wisconsin Electric Power CompanyThe remaining three of the ten direct subsidiaries were:

North American Utility Securities Corporation
West Kentucky Coal Company
60 Broadway Building CorporationAt various times during its existence, North American also owned substantial interests in these other companies as well:

The Milwaukee Electric Railway and Light Company: Formed in 1896 as a subsidiary of the North American Company  By 1929, it operated within North American Company along with Wisconsin Electric Power Company, which became the consolidated name of the two operating companies in 1938  It now belongs to Wisconsin Energy Corporation (NYSE: WEC)
Capital Transit: Formed on December 1, 1933, in Washington, D C  from merger of Washington Railway, Capital Traction, and Washington Rapid Transit  North American owned it through its holding company subsidiary, Washington Railway and Electric Company, which in turn was the holding company for the merged lines, owning 50% of Capital Transit 
Potomac Electric Power Company
Cincinnati Gas & Electric Company
Union Light, Heat and Power of Covington, Kentucky
Northern Natural Gas Company
Butte Electric and Power Company
Laclede Gas Company
Edison Securities Corporation
Wired Radio, Inc  (Muzak)
North American Edison Company
St  Louis United Railways Company

History
The Public Utility Holding Company Act of 1935 passed with the intent of breaking up interstate electric holding companies by limiting company operations to a single state, thus subjecting them to effective state regulation  The North American Company fought the legislation in court, and the company was not broken up by the Securities and Exchange Commission until their loss before the Supreme court in North American Co  v  SEC on April 1, 1946 

Dow Jones Industrial Average
North American's stock was one of the twelve component stocks of the May 1896 original Dow Jones Industrial Average, but it was replaced later that same year  In 1928, when the number of stocks comprising the DJIA was increased to 30, North American was re-added to the list but was replaced again in 1930  The two periods when it was a component were:

May 26, 1896 – August 26, 1896, replaced by U  S  Cordage
October 1, 1928 – January 29, 1930, replaced by Johns-Manville

See also
John I  Beggs (former director)
Clement Studebaker Jr  (chairman of North American Light and Power Co)
Passage 8:
Alfred A  Marcus
Alfred Allen Marcus (born 1950) is an American author and the Edson Spencer Professor of Strategy and Technology Leadership at the Carlson School of Management, University of Minnesota and the Technological Leadership Institute  He has worked as a consultant with companies such as 3M, Corning Inc , Xcel Energy, Medtronic, General Mills, and IBM and has also taught as a visiting professor at Technion, INCAE, BI Norwegian Business School, Fordham University, and MIT 

Environmental and energy policy career
Marcus was born in Pittsburgh, Pennsylvania and grew up in the Squirrel Hill neighborhood  He attended the University of Chicago for his bachelor's and master's degrees, before finishing his PhD in political science at Harvard University under James Q  Wilson  Outside academy, he has worked on environmental and energy policy analysis during the Carter and Reagan years at the Battelle Human Affairs Research Centers in Seattle, Washington  There he conducted and participated in studies on the commercialization of alternative energy technologies and new energy saving technologies 
Following the Three Mile Island nuclear power incident, he also became involved in the work carried out by the Nuclear Regulatory Commission on the organization and management of nuclear power plants  Marcus has written many academic articles relating to organizational safety in publications like the Academy of Management Journal, the Strategic Management Journal, and Organization Science 

Published works
His work focuses primarily on  the relationship between public policy, the environment, and American business and his books include: 

Promise and Performance: Choosing and Implementing an Environmental Policy (1980) - Praeger  ISBN 0-313-207070
The Adversary Economy (1984) - Praeger  ISBN 0-899-300553
Managing Environmental Issues: A Casebook (1992) - Prentice Hall  ISBN 0-135-638917
Controversial Issues in Energy Policy (1992) - SAGE Publications  ISBN 0-803-939701
Reinventing Environmental Regulation: Lessons from Project XL (2002) -Routledge  ISBN 1-891-853090
Strategic Foresight - A New Look at Scenarios (2010)  - Palgrave Macmillan  ISBN 0-230-611729
Innovations in Sustainability (2015) - Cambridge University Press  ISBN 1-107-42111X

Selected bibliography
See also
Paul Shrivastava
Passage 9:
North American Co  v  SEC
North American Co  v  Securities and Exchange Commission, 327 U S  686 (1946), is a United States Supreme Court case holding that a Securities and Exchange Commission (SEC) order under the Public Utility Holding Company Act (PUHCA) directing a public utility holding company to divest its securities of all companies except for one electric company did not violate the Commerce Clause or the Fifth Amendment to the United States Constitution 

Background
PUHCA was one of a number of trust-busting and securities regulation initiatives that were enacted in response to the Wall Street Crash of 1929 and ensuing Great Depression, including the collapse of Samuel Insull's public utility holding companies  By 1932, the eight largest utility holding companies controlled 73 percent of the investor-owned electric industry  Their complex, highly leveraged, corporate structures were very difficult for individual states to regulate  PUHCA required electric company holding companies to register with the SEC, and authorized the SEC to limit a holding company to a single integrated electric system through the divestiture of its other public utility and unrelated companies 
The North American Company, formed in 1890, was a holding company in a system that by 1940 contained 80 companies operating in seventeen states and the District of Columbia  These included the Union Electric Company, which operated an electric system around St  Louis, Missouri, and subsidiaries in Illinois and Iowa, the Washington Railway and Electric Company, and the North American Light and Power Company with systems in Kansas, Missouri, Illinois, and Iowa and its subsidiaries Cleveland Electric Illuminating Company, Pacific Gas and Electric, and Detroit Edison Company  In addition, North American also owned an investment trust company and West Kentucky Coal Company  Together the various electric systems served more than 3,000,000 customers in a service territory of 165,000 square miles 
North American initially challenged the constitutionality of PUHCA and requested an injunction against its enforcement, but the Supreme Court in Landis v  North American Co , held that the case was premature and that North American should register and then litigate the constitutionality of PUHCA after the SEC conducted its proceeding  North American then registered in 1937 as a holding company with the SEC, reserving its right to challenge the validity of the remaining portions of PUHCA  After initiating an administrative proceeding, the SEC issued an order requiring divestiture of North American's securities in companies other than the Union Electric Company  North American appealed, but in 1943 the Court of Appeals for the Second Circuit upheld the order  Arguing that ownership of securities was not interstate commerce within the meaning of the Commerce Clause and that the divestiture ordered by the SEC was a taking in violation of the Fifth Amendment, North American appealed to the Supreme Court, which granted certiorari 

Opinion
The opinion by Justice Murphy first concluded that North American was engaged in interstate commerce and through its substantial stock ownership dominated its subsidiaries  The opinion then noted that North American's argument that PUHCA's divestiture provision was invalid because ownership of securities was not commerce had been previously rejected by the Court in the anti-trust case of Northern Securities Co  v  United States  Under its authority under the Commerce Clause, Congress could regulate to protect the freedom of interstate commerce using any means that were lawful and not prohibited by the Constitution  Under Northern Securities, Congress could deal with and affect the ownership of securities to protect the freedom of commerce, which it did in fashioning the divestiture remedy in PUHCA 
Lastly, the Court dismissed the takings argument, noting that Congress had weighed the benefit to shareholders of efficient, common management of diversified companies against the actual and potential harm to the public, investors, and consumers from the use of pooled investments, and determined that the economic advantages of a holding company atop an unintegrated, sprawling electric system were not commensurate with the resulting economic disadvantages  In addition, it was not clear that there would be a loss necessary for a takings claim under the Fifth Amendment  PUHCA does not require the dumping or forced liquidation of the securities on the market for cash, so the stock of the companies ordered divested could be distributed to the shareholders or sold under a plan that protects shareholder rights  The Court determined that it could not conclude that North American shareholders were disadvantaged by the operation of the divestiture provision of PUHCA 
Justices Reed, Douglas and Jackson did not participate in the consideration of the case  Although Chief Justice Stone had initially recused himself for a disclosed reason, but when he discovered that his disqualification plus those of the other justices would result in the lack of a quorum, he reversed his position 

Subsequent events
PUHCA was repealed by the Energy Policy Act of 2005 effective February 8, 2006 

See also
List of United States Supreme Court cases, volume 327
Context 3: 
The local people in Band-e-Amir National Park rely heavily on the park's natural resources for their livelihood  Grazing of livestock, collection of shrubs for fuel and winter fodder and rain-fed farming is still widely practiced within the park boundary  Although the illegal hunting of birds and a few mammals living in the park is formally prohibited by the park office, there is no current data to evaluate the status of wildlife and biodiversity 

Important Bird Area
A 41,000 ha tract overlapping the national park has been designated an Important Bird Area (IBA) by BirdLife International because it supports populations of Himalayan snowcocks, Hume's larks, white-winged snowfinches, Afghan snowfinches and Eurasian crimson-winged finches 

See also
List of dams and reservoirs in Afghanistan
Natural areas of Afghanistan
Wakhan National Park
Nuristan National Park
Passage 2:
Qasim Oryakhail
Qasim Oryakhail (born 10 January 1992) is an Afghan cricketer  He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 12 September 2017  He made his first-class debut for Speen Ghar Region in the 2017–18 Ahmad Shah Abdali 4-day Tournament on 20 October 2017  He made his List A debut for Kabul Region in the 2018 Ghazi Amanullah Khan Regional One Day Tournament on 15 July 2018 
Passage 3:
Samim Sultani
Samim Sultani is an Afghan cricketer  He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 14 September 2017 
Passage 4:
Fitratullah Khawari
Fitratullah Khawari (born 29 January 1997) is an Afghan cricketer  He made his List A debut for Mis Ainak Region in the 2017 Ghazi Amanullah Khan Regional One Day Tournament on 10 August 2017  He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 18 September 2017  He made his first-class debut for Speen Ghar Region in the 2017–18 Ahmad Shah Abdali 4-day Tournament on 20 October 2017 In September 2018, he was named in Kabul's squad in the first edition of the Afghanistan Premier League tournament 
Passage 5:
Ikram Faizi
Ikram Alikhil (Pashto: اکرام فيضي عليخېل; born 29 September 2000) is an Afghan cricketer  He made his international debut for the Afghanistan cricket team in March 2019 

Domestic and U19 career
He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 14 September 2017  Prior to his T20 debut, he was part of Afghanistan's squad for the 2016 Under-19 Cricket World Cup  He also scored an unbeaten century in the final of the 2017 ACC Under-19 Asia Cup and helped Afghanistan to win their maiden ACC Under-19 Cup title In December 2017, he was named in Afghanistan's squad for the 2018 Under-19 Cricket World Cup He made his first-class debut for Speen Ghar Region in the 2018 Ahmad Shah Abdali 4-day Tournament on 1 March 2018  He made his List A debut for Speen Ghar Region in the 2018 Ghazi Amanullah Khan Regional One Day Tournament on 10 July 2018 In September 2018, he was named in Balkh's squad in the first edition of the Afghanistan Premier League tournament 

International career
In December 2018, he was named in Afghanistan's under-23 team for the 2018 ACC Emerging Teams Asia Cup In February 2019, he was named in Afghanistan's Test and One Day International (ODI) squads for their series against Ireland in India  He made his ODI debut for Afghanistan against Ireland on 2 March 2019  He made his Test debut for Afghanistan against Ireland on 15 March 2019 On 6 June 2019, he was added to Afghanistan's squad for the 2019 Cricket World Cup  He replaced Mohammad Shahzad, who was ruled out of the tournament due to a knee injury 
Passage 6:
Arif Khan (cricketer)
Arif Khan (born 5 June 2001) is an Afghan cricketer  He made his List A debut for Band-e-Amir Region in the 2017 Ghazi Amanullah Khan Regional One Day Tournament on 10 August 2017  He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 17 September 2017



ground_truth: Xcel Energy Inc.

prompt_front: Answer the question based on the given passages. Only give me the answer and do not output any other words.

Question: Band-e-Amir Dragons is named after the lakes in which Afghan national park?

The following are given passages.
Context 3:  He made his first-class debut for Speen Ghar Region in the 2017–18 Ahmad Shah Abdali 4-day Tournament on 7 November 2017 
Passage 7:
Muslim Musa
Muslim Musa (born 15 January 1997) is an Afghan cricketer  He made his List A debut for Amo Region in the 2017 Ghazi Amanullah Khan Regional One Day Tournament on 10 August 2017  Before his List A debut, he was part of Afghanistan's squad for the 2016 Under-19 Cricket World Cup He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 12 September 2017  He made his first-class debut for Speen Ghar Region in the 2017–18 Ahmad Shah Abdali 4-day Tournament on 20 October 2017 In September 2018, he was named in Kabul's squad in the first edition of the Afghanistan Premier League tournament 
Passage 8:
Band-e-Amir Dragons
Band-e-Amir Dragons (Pashto: بند امير ښاماران Band-e-Amīr Khāmārān / Shāmārān; Dari: بند امیر شاماران) or Band-e-Amir Region is one of eight regional first-class cricket teams in Afghanistan  In the 2017 Shpageeza team auction, the Band-e-Amir Dragons team was bought by Paragon Business Group, a Finance and investment company, and it will play as the Paragon Band-e-Amir Dragons in this competition  The Region represents the following provinces in the centre of Afghanistan: Ghazni, Bamyan, Daykundi, and Maidan Wardak  The team is named after Band-e Amir, a series of six deep blue lakes in Bamyan Province 
Band-e-Amir Region compete in the Ahmad Shah Abdali 4-day Tournament, which has had first-class status from 2017 onwards  In October 2017, they lost their opening fixture of the tournament, against Mis Ainak Region, by 262 runs They also play in the Ghazi Amanullah Khan Regional One Day Tournament, which was granted List A status from 2017  and the Afghan Shpageeza Cricket League Twenty20 competition (which has Twenty20 status from 2017) using the name Band-e-Amir Dragons 
Passage 9:
Shahidullah (cricketer)
Shahidullah (born 6 February 1999) is an Afghan cricketer  He made his List A debut for Afghanistan A against Zimbabwe A during their tour to Zimbabwe on 27 January 2017  Prior to his List A debut, he was named in Afghanistan's squad for the 2014 Under-19 Cricket World Cup  He made his international debut for the Afghanistan cricket team in March 2021 

Career
Shahidullah made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 12 September 2017  He made his first-class debut for Mis Ainak Region in the 2017–18 Ahmad Shah Abdali 4-day Tournament on 19 November 2017  He was the leading run-scorer for Mis Ainak Region in the 2018 Ahmad Shah Abdali 4-day Tournament, with 663 runs in eight matches In September 2018, Shahidullah was named in Kabul's squad in the first edition of the Afghanistan Premier League tournament  In December 2018, he was named in Afghanistan's under-23 team for the 2018 ACC Emerging Teams Asia Cup In August 2019, Shahidullah was named in Afghanistan's Twenty20 International (T20I) squad for the 2019–20 Bangladesh Tri-Nation Series  In November 2019, he was named in Afghanistan's squad for the 2019 ACC Emerging Teams Asia Cup in Bangladesh  In February 2021, he was named in Afghanistan's Test squad for their series against Zimbabwe  He made his Test debut for Afghanistan, against Zimbabwe, on 10 March 2021 In July 2021, Shahidullah was named in Afghanistan's One Day International (ODI) squad for their series against Pakistan  In January 2022, he was named in Afghanistan's ODI squad for their series against the Netherlands in Qatar  He made his ODI debut on 21 January 2022, for Afghanistan against the Netherlands 
Passage 10:
Javeed Khan
Javeed Khan is an Afghan cricketer  He made his Twenty20 debut for Band-e-Amir Dragons in the 2017 Shpageeza Cricket League on 21 September 2017 



ground_truth: Band-e Amir National Park