X-ray Crystallographic Structure of BshC, a Unique Enzyme Involved in Bacillithiol Biosynthesis

摘要

Bacillithiol is produced by many Gram-positive bacteria via a pathway utilizing the enzymes BshA, BshB, and BshC. Here we report the 1.77 angstrom resolution crystal structure of BshC, the putative cysteine ligase in bacillithiol production. The structure reveals that BshC contains a core Rossmann fold with connecting peptide motifs (CP1 and CP2) and a unique alpha-helical coiled-coil domain that facilitates dimerization. The model contains citrate and glycerol in the canonical active site and ADP in a second binding pocket. The overall structure and bound ligands give insight into the function of this unique enzyme.