Deinococcota
Deinococcota is a phylum of bacteria with a single class, Deinococci, that are highly resistant to environmental hazards, also known as extremophiles. These bacteria have thick cell walls that give them gram-positive stains, but they include a second membrane and so are closer in structure to those of gram-negative bacteria. Taxonomy. The phylum "Deinococcota" consists of a single class ("Deinococci") and two orders: Though these two groups evolved from a common ancestor, the two mechanisms of resistance appear to be largely independent. Molecular signatures. Molecular signatures in the form of conserved signature indels (CSIs) and proteins (CSPs ) have been found that are uniquely shared by all members belonging to the "Deinococcota" phylum. These CSIs and CSPs are distinguishing characteristics that delineate the unique phylum from all other bacterial organisms, and their exclusive distribution is parallel with the observed differences in physiology. CSIs and CSPs have also been found that support order and family-level taxonomic rankings within the phylum. Some of the CSIs found to support order level distinctions are thought to play a role in the respective extremophilic characteristics. The CSIs found in DNA-directed RNA polymerase subunit beta and DNA topoisomerase I in "Thermales" species  may be involved in thermophilicity, while those found in Excinuclease ABC, DNA gyrase, and DNA repair protein RadA in "Deinococcales" species may be associated with radioresistance. Two CSPs that were found uniquely for all members belonging to the "Deinococcus" genus are well characterized and are thought to play a role in their characteristic radioresistant phenotype. These CSPs include the DNA damage repair protein PprA the single-stranded DNA-binding protein DdrB. Additionally, some genera within this group, including "Deinococcus", "Thermus", and "Meiothermus", also have molecular signatures that demarcate them as individual genera, inclusive of their respective species, providing a means  to distinguish them from the rest of the group and all other bacteria. CSIs have also been found specific for "Truepera radiovictrix" . Phylogeny. The phylogeny is based on 16S rRNA-based LTP release 123 by 'The All-Species Living Tree' Project. Note: ♠ Strains found at the National Center for Biotechnology Information (NCBI) but not listed in the List of Prokaryotic names with Standing in Nomenclature (LSPN) Taxonomy. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) Sequenced genomes. Currently there are 10 sequenced genomes  of strains in this phylum. The two "Meiothermus" species were sequenced under the auspices of the Genomic Encyclopedia of Bacteria and Archaea project (GEBA), which aims at sequencing organisms based on phylogenetic novelty and not on pathogenicity or notoriety.