2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase

InterPro Family 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase 1.3.1.28 37250-40-1 0008667 In enzymology, 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase (1.3.1.28) is an enzyme that catalyzes the chemical reaction 50% Q27121410 2,3-Dihydroxy-2,3-dihydrobenzoic acid + NAD+ reversible H+ H+ 2,3-Dihydroxybenzoic acid + NADH The two substrates of this enzyme are (2S,3S)-2,3-dihydroxy-2,3-dihydrobenzoic acid and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are 2,3-dihydroxybenzoic acid, reduced NADH, and a proton.1.3.1.28 This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 2,3-dihydro-2,3-dihydroxybenzoate:NAD+ oxidoreductase. This enzyme is also called 2,3-diDHB dehydrogenase. This enzyme participates in biosynthesis of siderophore group nonribosomal. Young IG, Gibson F Regulation of the enzymes involved in the biosynthesis of 2,3-dihydroxybenzoic acid in Aerobacter aerogenes and Escherichia coli Biochimica et Biophysica Acta (BBA) - General Subjects 177 3 401–11 May 1969 4306838 10.1016/0304-4165(69)90302-X Structure left|thumb|Monomer structure of 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase. 2,3-diDHB dehydrogenase is a tetramer protein with dimension 65x69x43 Å. It has a crystallographic 222 symmetry, which exhibited for other members of short-chain oxireductase (SCOR) family of enzymes. The length of each monomer is 248 residues and the weight of the protein is 24647 Da. http://www.rcsb.org/pdb/explore/explore.do?structureId=2FWM Crystal Structure of E. coli EntA, a 2,3-dihydrodihydroxy benzoate dehydrogenase n.d. 19 April 2015 RCSB Protein Data Bank Each monomer consists of 7 beta-pleated sheets and 6 alpha helices. Although the structure of the binding protein is not clearly defined, it was proposed that the binding pocket is made out of Leu83, Met85, Arg138, Gly140, Met141, Ser176, Met181, Gln182 and Leu185. It was also speculated that Arg138 is a likely subunit that interacts with the carboxyl group of 2,3-diDHB. Since there was a strong indication of oxidation at C3 position, Sakaitani M, Rusnak F, Quinn NR, Tu C, Frigo TB, Berchtold GA, Walsh CT Mechanistic studies on trans-2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase (Ent A) in the biosynthesis of the iron chelator enterobactin Biochemistry 29 29 6789–98 July 1990 2144454 10.1021/bi00481a006 Ser176 and Gln182 interact with the C2-hydroxyl group in order for the stereo-selective reaction to occur. Reaction mechanism thumb|Reaction scheme for 2,3-diDHB dehydrogenase. In times of limited iron number in the environment, the EntA reaction is irreversible physiologically. The exact mechanism for the reaction is unknown; however, the proposed reaction scheme for the reaction is as following: Rate of reaction The rate of the conversion reaction is determined by several factors. The regiochemical position of the carboxyl group and the 3-hydroxyl group plays one role in the reaction, in which the rate of reaction of 1,3-cis-substituted substrate gives about 40-fold higher kcat/Km value than the 1,3-trans-substituted substrate. Roles in bacteria E. coli 2,3-diDHB dehydrogenase catalyzes the NAD+-dependent oxidation of 2,3-dihydro-2,3-dihydroxybenzoate to produce an aromatic compound 2,3-dihydroxybenzoic acid (2,3-DHB or simply DHB). In times of iron deficiency, iron uptake is controlled by three genes: ent, fep, and fes for synthesis, export, and uptake of ferric Enterobactin and its hydrolytic cleavage to release Fe3+ into the cell. This production of this compound is controlled by eight genes: entA-entF, Sundlov JA, Garringer JA, Carney JM, Reger AS, Drake EJ, Duax WL, Gulick AM Determination of the crystal structure of EntA, a 2,3-dihydro-2,3-dihydroxybenzoic acid dehydrogenase from Escherichia coli Acta Crystallographica D 62 Pt 7 734–40 July 2006 16790929 10.1107/S0907444906015824 entH, Khalil S, Pawelek PD Enzymatic adenylation of 2,3-dihydroxybenzoate is enhanced by a protein-protein interaction between Escherichia coli 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase (EntA) and 2,3-dihydroxybenzoate-AMP ligase (EntE) Biochemistry 50 4 533–45 February 2011 21166461 10.1021/bi101558v and entS. In E. coli, all of these genes are controlled by the Fur repressor, such that the genes are turned on when the concentration of iron in the environment is low. From these six genes, EntA, EntB, and EntC are responsible for the synthesis of DHB from chorismic acid and the gene EntA encodes the information of 2,3-diDHB dehydrogenase. Without entA, entB, and entC, the bacteria show almost an absolute requirement of DHB in order to survive. Young IG, Langman L, Luke RK, Gibson F Biosynthesis of the iron-transport compound enterochelin: mutants of Escherichia coli unable to synthesize 2,3-dihydroxybenzoate Journal of Bacteriology 106 1 51–7 April 1971 4928016 248643 10.1128/JB.106.1.51-57.1971 A. tumefaciens Production of siderophores also exhibited in some plant-infecting bacteria, such as Agrobacterium tumefaciens. Sonoda H, Suzuki K, Yoshida K Gene cluster for ferric iron uptake in Agrobacterium tumefaciens MAFF301001 Genes & Genetic Systems 77 3 137–46 June 2002 12207035 10.1266/ggs.77.137 free The enzyme is controlled by gene cluster agb and the production of 2,3-diDHB dehydrogenase is controlled by the gene agbA. The enzyme AgbA is homologous to the EntA enzyme in E. coli, the same enzyme that produces 2,3-diDHB dehydrogenase. References 32em Biology no Category:EC 1.3.1 Category:NADH-dependent enzymes Category:Enzymes of known structure