Structure of geranyl diphosphate C-methyltransferase from Streptomyces coelicolor and implications for the mechanism of isoprenoid modification.

ABSTRACT: Geranyl diphosphate C-methyltransferase (GPPMT) from Streptomyces coelicolor A3(2) is the first methyltransferase discovered that modifies an acyclic isoprenoid diphosphate, geranyl diphosphate (GPP), to yield a noncanonical acyclic allylic diphosphate product, 2-methylgeranyl diphosphate, which serves as the substrate for a subsequent cyclization reaction catalyzed by a terpenoid cyclase, methylisoborneol synthase. Here, we report the crystal structures of GPPMT in complex with GPP or the substrate analogue geranyl S-thiolodiphosphate (GSPP) along with S-adenosyl-L-homocysteine in the cofactor binding site, resulting from in situ demethylation of S-adenosyl-L-methionine, at 2.05 or 1.82 Å resolution, respectively. These structures suggest that both GPP and GSPP can undergo catalytic methy

SUBMITTER: Koksal M 

PROVIDER: S-EPMC3323675 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature