Reaction: dTDP-4-dehydro-6-deoxy-α-D-glucopyranose = dTDP-3,4-didehydro-2,6-dideoxy-α-D-glucose + H2O (overall reaction)
(1a) dTDP-4-dehydro-6-deoxy-α-D-glucopyranose = dTDP-2,6-dideoxy-D-glycero-hex-2-enos-4-ulose + H2O
(1b) dTDP-2,6-dideoxy-D-glycero-hex-2-enos-4-ulose = dTDP-3,4-didehydro-2,6-dideoxy-α-D-glucose (spontaneous)
For diagram of reaction click here.
Other name(s): jadO (gene name); evaA (gene name); megBVI (gene name); eryBV (gene name); mtmV (gene name); oleV (gene name); spnO (gene name); TDP-4-keto-6-deoxy-D-glucose 2,3-dehydratase; dTDP-4-dehydro-6-deoxy-α-D-glucopyranose hydro-lyase (dTDP-(2R,6S)-2,4-dihydroxy-6-methyl-2,6-dihydropyran-3-one-forming)
Systematic name: dTDP-4-dehydro-6-deoxy-α-D-glucopyranose hydro-lyase (dTDP-2,6-dideoxy-D-glycero-hex-2-enos-4-ulose-forming)
Comments: The enzyme participates in the biosynthesis of several deoxysugars, including β-L-4-epi-vancosamine, α-L-megosamine, L- and D-olivose, D-oliose, D-mycarose, forosamine and β-L-digitoxose. In vitro the intermediate can undergo a spontaneous decomposition to maltol [2,3].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Aguirrezabalaga, I., Olano, C., Allende, N., Rodriguez, L., Brana, A.F., Mendez, C. and Salas, J.A. Identification and expression of genes involved in biosynthesis of L-oleandrose and its intermediate L-olivose in the oleandomycin producer Streptomyces antibioticus. Antimicrob. Agents Chemother. 44 (2000) 1266-1275. [PMID: 10770761]
2. Chen, H., Thomas, M.G., Hubbard, B.K., Losey, H.C., Walsh, C.T. and Burkart, M.D. Deoxysugars in glycopeptide antibiotics: enzymatic synthesis of TDP-L-epivancosamine in chloroeremomycin biosynthesis. Proc. Natl. Acad. Sci. USA 97 (2000) 11942-11947. [PMID: 11035791]
3. Gonzalez, A., Remsing, L.L., Lombo, F., Fernandez, M.J., Prado, L., Brana, A.F., Kunzel, E., Rohr, J., Mendez, C. and Salas, J.A. The mtmVUC genes of the mithramycin gene cluster in Streptomyces argillaceus are involved in the biosynthesis of the sugar moieties. Mol. Gen. Genet. 264 (2001) 827-835. [PMID: 11254130]
4. Wang, L., White, R.L. and Vining, L.C. Biosynthesis of the dideoxysugar component of jadomycin B: genes in the jad cluster of Streptomyces venezuelae ISP5230 for L-digitoxose assembly and transfer to the angucycline aglycone. Microbiology 148 (2002) 1091-1103. [PMID: 11932454]
5. Hong, L., Zhao, Z., Melancon, C.E., 3rd, Zhang, H. and Liu, H.W. In vitro characterization of the enzymes involved in TDP-D-forosamine biosynthesis in the spinosyn pathway of Saccharopolyspora spinosa. J. Am. Chem. Soc. 130 (2008) 4954-4967. [PMID: 18345667]
6. Useglio, M., Peiru, S., Rodriguez, E., Labadie, G.R., Carney, J.R. and Gramajo, H. TDP-L-megosamine biosynthesis pathway elucidation and megalomicin a production in Escherichia coli. Appl. Environ. Microbiol. 76 (2010) 3869-3877. [PMID: 20418422]