Reaction: D-sedoheptulose 7-phosphate = 2-epi-valiolone + phosphate
For diagram of reaction click here.
Glossary: 2-epi-valiolone = (2S,3S,4S,5S)-2,3,4,5-tetrahydroxy-5-(hydroxymethyl)cyclohexan-1-one
Systematic name: D-sedoheptulose-7-phosphate phosphate-lyase (cyclizing; 2-epi-valiolone-forming)
Comments: The enzyme, characterized from the bacteria Actinosynnema mirum and Stigmatella aurantiaca DW4/3-1, produces 2-epi-valiolone, which is believed to function as a precursor in aminocyclitol biosynthesis. It requires a divalent metal ion (Zn2+ or Co2+) and an NAD+ cofactor, which is transiently reduced during the reaction. cf. EC 18.104.22.168, 2-epi-5-epi-valiolone synthase and EC 22.214.171.124, desmethyl-4-deoxygadusol synthase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Asamizu, S., Xie, P., Brumsted, C.J., Flatt, P.M. and Mahmud, T. Evolutionary divergence of sedoheptulose 7-phosphate cyclases leads to several distinct cyclic products. J. Am. Chem. Soc. 134 (2012) 12219-12229. [PMID: 22741921]