Crystal structure of glutamate-1-semialdehyde aminomutase: an alpha2-dimeric vitamin B6-dependent enzyme with asymmetry in structure and active site reactivity.

ABSTRACT: The three-dimensional structure of glutamate-1-semialdehyde aminomutase (EC 5.4.3.8), an alpha2-dimeric enzyme from Synechococcus, has been determined by x-ray crystallography using heavy atom derivative phasing. The structure, refined at 2.4-A resolution to an R-factor of 18.7% and good stereochemistry, explains many of the enzyme's unusual specificity and functional properties. The overall fold is that of aspartate aminotransferase and related B6 enzymes, but it also has specific features. The structure of the complex with gabaculine, a substrate analogue, shows unexpectedly that the substrate binding site involves residues from the N-terminal domain of the molecule, notably Arg-32. Glu-406 is suitably positioned to repel alpha-carboxylic acids, thereby suggesting a basis for the enzyme'

SUBMITTER: Hennig M 

PROVIDER: S-EPMC24597 | biostudies-literature | 1997 May

REPOSITORIES: biostudies-literature