Insights into the catalytic mechanism of Grimontia hollisae collagenase through structural and mutational analyses.

Grimontia hollisae collagenase (Ghcol) consists of 767 amino acid residues with a single catalytic domain containing the zinc-binding motif H 492 EYVH 496 . The crystal structure of Ghcol in complex with its substrate (Gly-Pro-hydroxyproline-Gly-Pro-hydroxyproline) and site-directed mutagenesis of active-site Tyr residues revealed the catalytic mechanism: Glu493 functions as an acid and base catalyst while Tyr564 stabilizes the tetrahedral complex in the transition state.