If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Locations of Mapped Genes:
|Superclasses:||Biosynthesis → Amino Acids Biosynthesis → Proteinogenic Amino Acids Biosynthesis → L-valine Biosynthesis|
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
Flint93a: 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
AlexanderCaudle90: Alexander-Caudle C, Latinwo LM, Jackson JH (1990). "Acetohydroxy acid synthase activity from a mutation at ilvF in Escherichia coli K-12." J Bacteriol 1990;172(6);3060-5. PMID: 2188950
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
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
Engel04: Engel S, Vyazmensky M, Berkovich D, Barak Z, Chipman DM (2004). "Substrate range of acetohydroxy acid synthase I from Escherichia coli in the stereoselective synthesis of alpha-hydroxy ketones." Biotechnol Bioeng 88(7);825-31. PMID: 15558598
Eoyang86: Eoyang L, Silverman PM (1986). "Role of small subunit (IlvN polypeptide) of acetohydroxyacid synthase I from Escherichia coli K-12 in sensitivity of the enzyme to valine inhibition." J Bacteriol 166(3);901-4. PMID: 3011751
Showing only 20 references. To show more, press the button "Show all references".
©2016 SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-3493