X-Ray snapshots of a pyridoxal enzyme: a catalytic mechanism involving concerted [1,5]-hydrogen sigmatropy in methionine γ-lyase.

ABSTRACT: Pyridoxal 5'-phosphate (PLP)-enzymes are essentially involved in amino acid and amine metabolism of a wide variety of organisms. Despite their extensive biochemical studies, there are little evidence and structural data to comprehensively elaborate the catalytic mechanism. We obtained X-ray snapshots of l-methionine γ-lyase from Entamoeba histolytica (EhMGL), a PLP-enzyme catalyzing the γ-elimination reaction of methionine. Here, we suggest a catalytic mechanism of EhMGL by using the X-ray snapshots covering all stages of this multistep catalysis reaction. Initial formation of a Michaelis complex is followed by the migration of double bond from the C4'=Nα-Cα moiety in an intermediate PLP-methionine imine to C4'-Nα=Cα in pyridoxamine 5'-phosphate (PMP)-α,β-dehydromethionine imine without in

SUBMITTER: Sato D 

PROVIDER: S-EPMC5501846 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature