Pericyclic reactions catalyzed by chorismate-utilizing enzymes

This publication was made possible by funds from National Institutes of Health (NIH) Grant P20 RR016475 from the INBRE Program of the National Center for Research Resources and NIH Grants R01 AI77725 and K02 AI093675 from the National Institute for Allergy and Infectious Diseases. ; One of the fundamental questions of enzymology is how catalytic power is derived. This review focuses on recent developments in the structure-function relationships of chorismate-utilizing enzymes involved in siderophore biosynthesis to provide insight into the biocatalysis of pericyclic reactions. Specifically, salicylate synthesis by the two-enzyme pathway in Pseudomonas aeruginosa is examined. The isochorismate-pyruvate lyase is discussed in the context of its homologues, the chorismate mutases, and the isochorismate synthase is compared to its homologues in the MST-family (menaquinone, siderophore or tryptophan biosynthesis) of enzymes. The tentative conclusion is that the activities observed cannot be reconciled by inspection of the active site participants alone. Instead, individual activities must arise from unique dynamic properties of each enzyme that are tuned to promote specific chemistries.