Structure and possible mechanism of the CcbJ methyltransferase from Streptomyces caelestis

The 2.7 Å resolution crystal structure of the CcbJ methyltransferase from S. caelestis, which is part of the biosynthetic pathway of the lincosamide antibiotic celesticetin, is reported along with its complex with S-adenosyl-L-homocysteine at 2.9 Å resoution. Mutational and docking studies based on these structures are used to propose a plausible mechanism for its activity.