Role of motif III in catalysis by acetyl-CoA synthetase.

ABSTRACT: The acyl-adenylate-forming enzyme superfamily, consisting of acyl- and aryl-CoA synthetases, the adenylation domain of the nonribosomal peptide synthetases, and luciferase, has three signature motifs (I-III) and ten conserved core motifs (A1-A10), some of which overlap the signature motifs. The consensus sequence for signature motif III (core motif A7) in acetyl-CoA synthetase is Y-X-S/T/A-G-D, with an invariant fifth position, highly conserved first and fourth positions, and variable second and third positions. Kinetic studies of enzyme variants revealed that an alteration at any position resulted in a strong decrease in the catalytic rate, although the most deleterious effects were observed when the first or fifth positions were changed. Structural modeling suggests that the highly conse

SUBMITTER: Ingram-Smith C 

PROVIDER: S-EPMC3438747 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature