The UbiX flavin prenyltransferase reaction mechanism resembles class I terpene cyclase chemistry.

ABSTRACT: The UbiX-UbiD enzymes are widespread in microbes, acting in concert to decarboxylate alpha-beta unsaturated carboxylic acids using a highly modified flavin cofactor, prenylated FMN (prFMN). UbiX serves as the flavin prenyltransferase, extending the isoalloxazine ring system with a fourth non-aromatic ring, derived from sequential linkage between a dimethylallyl moiety and the FMN N5 and C6. Using structure determination and solution studies of both dimethylallyl monophosphate (DMAP) and dimethyallyl pyrophosphate (DMAPP) dependent UbiX enzymes, we reveal the first step, N5-C1' bond formation, is contingent on the presence of a dimethylallyl substrate moiety. Hence, an S_N1 mechanism similar to other prenyltransferases is proposed. Selected variants of the (pyro)phosphate binding

SUBMITTER: Marshall SA 

PROVIDER: S-EPMC6541611 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature