Lysine221 is the general base residue of the isochorismate synthase from Pseudomonas aeruginosa (PchA) in a reaction that is diffusion limited.

ABSTRACT: The isochorismate synthase from Pseudomonas aeruginosa (PchA) catalyzes the conversion of chorismate to isochorismate, which is subsequently converted by a second enzyme (PchB) to salicylate for incorporation into the salicylate-capped siderophore pyochelin. PchA is a member of the MST family of enzymes, which includes the structurally homologous isochorismate synthases from Escherichia coli (EntC and MenF) and salicylate synthases from Yersinia enterocolitica (Irp9) and Mycobacterium tuberculosis (MbtI). The latter enzymes generate isochorismate as an intermediate before generating salicylate and pyruvate. General acid-general base catalysis has been proposed for isochorismate synthesis in all five enzymes, but the residues required for the isomerization are a matter of debate, with both

SUBMITTER: Meneely KM 

PROVIDER: S-EPMC3784010 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature