This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Biosynthesis → Amino Acids Biosynthesis → Proteinogenic Amino Acids Biosynthesis → L-valine Biosynthesis|
Some taxa known to possess this pathway include : Escherichia coli K-12 substr. MG1655, Methanococci, Methanococcus, Methanococcus aeolicus, Methanococcus maripaludis, Methanococcus voltae, Ralstonia eutropha H16
The pathway of valine biosynthesis is a four-step pathway that shares all of its steps with the parallel pathway of isoleucine biosynthesis. These entwined pathways are part of the superpathway of branched amino acid biosynthesis, that generates not only isoleucine and valine, but also leucine.
As a consequence of having several of its component enzymes involved in the synthesis of three different amino acids, the pathway of isoleucine biosynthesis is subject to regulation by all three amino acids. The first step in the pathway is primarily inhibited by valine, along with inhibition by isoleucine and leucine. The potential disruption this might cause to the parallel isoleucine biosynthesis pathway step using the same enzymes is resolved by upregulation of an earlier step that is unique to isoleucine biosynthesis, as explained in the L-isoleucine biosynthesis I (from threonine) summary. In this way, valine biosynthesis can be regulated independently of isoleucine biosynthesis, despite all four valine biosynthesis enzymes also participating in isoleucine biosynthesis.
Citations: [Neidhardt96 ]
Superpathways: superpathway of branched amino acid biosynthesis
Unification Links: EcoCyc:VALSYN-PWY
Flint93b: Flint DH, Emptage MH, Finnegan MG, Fu W, Johnson MK (1993). "The role and properties of the iron-sulfur cluster in Escherichia coli dihydroxy-acid dehydratase." J Biol Chem 1993;268(20);14732-42. PMID: 8325851
LeePeng79: Lee-Peng FC, Hermodson MA, Kohlhaw GB (1979). "Transaminase B from Escherichia coli: quaternary structure, amino-terminal sequence, substrate specificity, and absence of a separate valine-alpha-ketoglutarate activity." J Bacteriol 1979;139(2);339-45. PMID: 378964
Neidhardt96: Neidhardt FC, Curtiss III R, Ingraham JL, Lin ECC, Low Jr KB, Magasanik B, Reznikoff WS, Riley M, Schaechter M, Umbarger HE "Escherichia coli and Salmonella, Cellular and Molecular Biology, Second Edition." American Society for Microbiology, Washington, D.C., 1996.
Vinogradov06: Vinogradov V, Vyazmensky M, Engel S, Belenky I, Kaplun A, Kryukov O, Barak Z, Chipman DM (2006). "Acetohydroxyacid synthase isozyme I from Escherichia coli has unique catalytic and regulatory properties." Biochim Biophys Acta 1760(3);356-63. PMID: 16326011
Altmiller70: Altmiller DH, Wagner RP (1970). "Purification and properties of dihydroxy acid dehydratase from soluble and mitochondrial fractions of Neurospora crassa." Arch Biochem Biophys 138(1);160-70. PMID: 4986563
Barak12: Barak Z, Chipman DM (2012). "Allosteric regulation in Acetohydroxyacid Synthases (AHASs)--different structures and kinetic behavior in isozymes in the same organisms." Arch Biochem Biophys 519(2);167-74. PMID: 22198286
Bowen97: Bowen TL, Union J, Tumbula DL, Whitman WB (1997). "Cloning and phylogenetic analysis of the genes encoding acetohydroxyacid synthase from the archaeon Methanococcus aeolicus." Gene 188(1);77-84. PMID: 9099862
Burns95: Burns DM, Burger MJ, Beacham IR (1995). "Silent genes in bacteria: the previously designated 'cryptic' ilvHI locus of 'Salmonella typhimurium LT2' is active in natural isolates." FEMS Microbiol Lett 131(2);167-72. PMID: 7557326
Dailey86: Dailey FE, Cronan JE (1986). "Acetohydroxy acid synthase I, a required enzyme for isoleucine and valine biosynthesis in Escherichia coli K-12 during growth on acetate as the sole carbon source." J Bacteriol 1986;165(2);453-60. PMID: 3511034
Daniels92: Daniels DL, Plunkett G, Burland V, Blattner FR (1992). "Analysis of the Escherichia coli genome: DNA sequence of the region from 84.5 to 86.5 minutes." Science 1992;257(5071);771-8. PMID: 1379743
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Eden96: Eden A, Simchen G, Benvenisty N (1996). "Two yeast homologs of ECA39, a target for c-Myc regulation, code for cytosolic and mitochondrial branched-chain amino acid aminotransferases." J Biol Chem 271(34);20242-5. PMID: 8702755
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