1 - phosphofructokinase - wikipedia 1 - phosphofructokinase This article needs attention from an expert in Molecular and Cellular Biology or Biochemistry. The specific problem is : Article may contain errors caused by the confusion between 1 - phosphofructokinase ( EC 2.7. 1.56 ) and phosphofructokinase 1 ( EC 2.7. 1.11 ). WikiProject Molecular and Cellular Biology or WikiProject Biochemistry may be able to help recruit an expert. ( April 2017 ) Phosphofructokinase 1 ( PFK1 ) Identifiers EC number 2.7. 1.56 CAS number 37278 - 03 - 8 Databases IntEnz IntEnz view BRENDA BRENDA entry ExPASy NiceZyme view KEGG KEGG entry MetaCyc metabolic pathway PRIAM profile PDB structures RCSB PDB PDBe PDBsum Gene Ontology AmiGO / QuickGO show Search PMC articles PubMed articles NCBI proteins In enzymology, 1 - phosphofructokinase ( PFK1 ) ( EC 2.7. 1.56 ) is an enzyme that catalyzes the chemical reaction ATP + D - fructose 1 - phosphate → ADP + D - fructose 1, 6 - bisphosphate Thus, the two substrates of this enzyme are ATP and D - fructose 1 - phosphate, whereas its two products are ADP and D - fructose 1, 6 - bisphosphate. This enzyme belongs to the phosphofructokinase B ( PfkB ) or Ribokinase family of sugar kinases, specifically those transferring phosphorus - containing groups ( phosphotransferases ) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP : D - fructose - phosphate 6 - phosphotransferase. Other names in common use include fructose - 1 - phosphate kinase, 1 - phosphofructokinase ( phosphorylating ), D - fructose - 1 - phosphate kinase, fructose 1 - phosphate kinase, and 1 - phosphofructokinase. This enzyme participates in fructose and mannose metabolism. The members of the PfkB / RK family are identified by the presence of three conserved sequence motifs and their enzymatic activity generally shows a dependence on the presence of pentavalent ions. Contents 1 Structure 2 Function 3 Regulation 3.1 Cellular 3.1. 1 Hormonal 4 Clinical Significance 5 References Structure As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 2JG5. 1 - Phosphofructokinase is a tetramer of 4 identical subunits that each have a catalytic site. In addition to the catalytic binding sites, there are 4 additional binding sites for allosteric regulation. Function 1 - phosphofructokinase catalyzes the committed step of glycolysis. This step can be a rate limiting step in glycolysis, and may be regulated to establish the rate of glucose oxidation in the cell. This reaction is a phosphoryl group transfer from ATP to fructose 6 - phosphate, yielding fructose 1, 6 - biphosphate. The reaction is highly exergonic and is irreversible within the cell, though can be bypassed in gluconeogenesis via the enzyme fructose 1, 6 - bisphosphatase. Regulation Cellular The regulation of 1 - phosphofructokinase occurs primarily by allosteric effectors, and is based on the cell 's energy needs. There are two ATP binding sites ; a substrate site where the phosphate transfer occurs, and an allosteric site where allosteric regulation occurs. ATP acts as an allosteric inhibitor and when cellular concentrations of ATP are high, and the cell 's energy needs are low, the reaction catalyzed by 1 - phosphofructokinase is inhibited. When the cell is actively consuming ATP and stores deplete, the concentration of ATP lowers while the concentrations of AMP and ADP increase. AMP and ADP are both positive effectors of 1 - phosphofructokinase and bind allosterically to activate the reaction. This activation encourages glycolysis and ATP production. Inhibition can also occur via citrate, a product of glycolysis and intermediate in the citric acid cycle. An increased concentration of citrate indicates the cell is meeting current energy needs, and therefore encourages allosteric inhibition of 1 - phosphofructokinase allosterically via ATP. Hormonal Allosteric regulation of 1 - phosphofructokinase is facilitated hormonally to help the liver to maintain blood glucose levels. This is achieved in part by increasing or decreasing rates of glycolysis. When blood glucose levels are low, the secretion of glucagon leads to the phosphorylation of phosphofructokinase 2 which inhibits formation of fructose 2, 6 - bisphosphate. Therefore, when glucagon inhibits phosphofructokinase 2, cellular levels of fructose 2, 6 - bisphosphate decrease, and reduce activation of 1 - phosphofructokinase, ultimately reducing the rate of glycolysis within the cell. When 1 - phosphofructokinase is inhibited, rates of gluconeogenesis increase, further aiding an increase in blood sugar. When blood sugar is high, however, the secretion of insulin produces the opposite effect by removing the phosphate group from phosphofructokinase 2, which leads to activation, and formation of fructose 2, 6 - bisphosphate. As concentrations of fructose 2, 6 - bisphosphate increase, 1 - phosphofructokinase is allosterically activated, and rates of glycolysis increase, consuming glucose. At the same time the rate of gluconeogenesis decrease, also contributing to lowering blood sugar levels. Clinical significance A deficiency of 1 - phosphofructokinase can be inherited due to the genetic disorder glycogenosis type VII Tarui 's disease. Research has shown that this disease can lead to insulin resistance and reduced insulin secretion by beta cells in the pancreas, leading to non-insulin - dependent diabetes mellitus, or diabetes type 2. Non-insulin - dependent diabetes mellitus is considered a global epidemic by the World Health Organization. References ^ Jump up to : Park J, Gupta RS : Adenosine kinase and ribokinase -- the RK family of proteins. Cell Mol Life Sci 2008, 65 : 2875 - 2896. ^ Jump up to : Bork P, Sander C, Valencia A : Convergent evolution of similar enzymatic function on different protein folds : the hexokinase, ribokinase, and galactokinase families of sugar kinases. Protein Sci 1993, 2 : 31 - 40. Jump up ^ Maj MC, Singh B, Gupta RS : Pentavalent ions dependency is a conserved property of adenosine kinase from diverse sources : identification of a novel motif implicated in phosphate and magnesium ion binding and substrate inhibition. Biochemistry 2002, 41 : 4059 - 4069. ^ Jump up to : Nelson, David L. ( 2008 ). Lehninger Principles of Biochemistry. W.H. Freeman and company. p. 586. Jump up ^ Nelson, David L. ( 2008 ). Lehninger Principles of Biochemistry. W.H. Freeman and company. p. 532. Jump up ^ Ristow, M., Vorgerd, M., Möhlig, M., Schatz, H., & Pfeiffer, A. ( 1997 ). Deficiency of phosphofructo - 1 - kinase / Muscle subtype in humans impairs insulin secretion and causes insulin resistance. Journal of Clinical Investigation, 100 ( 11 ), 2833 -- 2841. Jump up ^ `` Diabetes Fact sheet N ° 312 ''. World Health Organization. Aug 2011. Archived from the original on 26 August 2013. Retrieved 21 March 2012. Reeves RE, Warren LG, Hsu DS ( 1966 ). `` 1 - Phosphofructokinase from an anaerobe ''. J. Biol. Chem. 241 ( 6 ) : 1257 -- 61. PMID 4222878. Sapico V, Anderson RL ( 1969 ). `` D - fructose 1 - phosphate kinase and D - fructose 6 - phosphate kinase from Aerobacter aerogenes. A comparative study of regulatory properties ''. J. Biol. Chem. 244 ( 22 ) : 6280 -- 8. PMID 4242639. Transferases : phosphorus - containing groups ( EC 2.7 ) 2.7. 1 - 2.7. 4 : phosphotransferase / kinase ( PO ) 2.7. 1 : OH acceptor Hexo - Gluco - Fructo - Hepatic Galacto - Phosphofructo - Liver Muscle Platelet Riboflavin Shikimate Thymidine ADP - thymidine NAD Glycerol Pantothenate Mevalonate Pyruvate Deoxycytidine PFP Diacylglycerol Phosphoinositide 3 Class I PI 3 Class II PI 3 Sphingosine Glucose - 1, 6 - bisphosphate synthase 2.7. 2 : COOH acceptor Phosphoglycerate Aspartate kinase 2.7. 3 : N acceptor Creatine 2.7. 4 : PO acceptor Phosphomevalonate Adenylate Nucleoside - diphosphate Uridylate Guanylate Thiamine - diphosphate 2.7. 6 : diphosphotransferase ( P O ) Ribose - phosphate diphosphokinase Thiamine diphosphokinase 2.7. 7 : nucleotidyltransferase ( PO - nucleoside ) Polymerase DNA polymerase DNA - directed DNA polymerase II III IV V RNA - directed DNA polymerase Reverse transcriptase Telomerase DNA nucleotidylexotransferase / Terminal deoxynucleotidyl transferase RNA nucleotidyltransferase RNA polymerase / DNA - directed RNA polymerase RNA polymerase I II III IV V Primase RNA - dependent RNA polymerase PNPase Phosphorolytic 3 ' to 5 ' exoribonuclease RNase PH PNPase Nucleotidyltransferase UTP -- glucose - 1 - phosphate uridylyltransferase Galactose - 1 - phosphate uridylyltransferase Guanylyltransferase mRNA capping enzyme Other Recombinase ( Integrase ) Transposase 2.7. 8 : miscellaneous Phosphatidyltransferases CDP - diacylglycerol -- glycerol - 3 - phosphate 3 - phosphatidyltransferase CDP - diacylglycerol -- serine O - phosphatidyltransferase CDP - diacylglycerol -- inositol 3 - phosphatidyltransferase CDP - diacylglycerol -- choline O - phosphatidyltransferase Glycosyl - 1 - phosphotransferase N - acetylglucosamine - 1 - phosphate transferase 2.7. 10 - 2.7. 13 : protein kinase ( PO ; protein acceptor ) 2.7. 10 : protein - tyrosine see tyrosine kinases 2.7. 11 : protein - serine / threonine see serine / threonine - specific protein kinases 2.7. 12 : protein - dual - specificity see serine / threonine - specific protein kinases 2.7. 13 : protein - histidine Protein - histidine pros - kinase Protein - histidine tele - kinase Histidine kinase Enzymes Activity Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Catalytically perfect enzyme Coenzyme Cofactor Enzyme catalysis Regulation Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator Classification EC number Enzyme superfamily Enzyme family List of enzymes Kinetics Enzyme kinetics Eadie -- Hofstee diagram Hanes -- Woolf plot Lineweaver -- Burk plot Michaelis -- Menten kinetics Types EC1 Oxidoreductases ( list ) EC2 Transferases ( list ) EC3 Hydrolases ( list ) EC4 Lyases ( list ) EC5 Isomerases ( list ) EC6 Ligases ( list ) Molecular and Cellular Biology portal Retrieved from `` https://en.wikipedia.org/w/index.php?title=1-phosphofructokinase&oldid=811336423 '' Categories : EC 2.7. 1 Enzymes of known structure Hidden categories : Articles needing expert attention from April 2017 All articles needing expert attention Molecular and Cellular Biology articles needing expert attention Biochemistry articles needing expert attention Talk Search Contents About Wikipedia Српски / srpski Srpskohrvatski / српскохрватски Edit links This page was last edited on 21 November 2017, at 00 : 00 ( UTC ). 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Question: how many binding sites for atp are there in pfk
Answer: two