Diverse roles of glycine residues conserved in photoactive yellow proteins.

ABSTRACT: The role of glycine residues was studied by alanine-scanning mutagenesis using photoactive yellow protein, a structural prototype of PER ARNT SIM domain proteins, as a template. Mutation of glycine located close to the end of beta-strands with dihedral angles disallowed for alanine (Gly-37, Gly-59, Gly-86, and Gly-115) induces destabilization of the protein structure. On the other hand, substitution for Gly-77 and Gly-82, incorporated into the fifth alpha-helix, slows the photocycle by 15-20 times, suggesting that these residues regulate the light-induced structural switch between dark-state structure and signaling-state structure. Most importantly, a significant amount of G29A is in the bleached state and showed a 1000-fold slower photocycle. As O(epsilon2) of the carboxylic acid of Glu-4

SUBMITTER: Imamoto Y 

PROVIDER: S-EPMC2292373 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature