Mechanism and energetics of green fluorescent protein chromophore synthesis revealed by trapped intermediate structures.

ABSTRACT: Green fluorescent protein has revolutionized cell labeling and molecular tagging, yet the driving force and mechanism for its spontaneous fluorophore synthesis are not established. Here we discover mutations that substantially slow the rate but not the yield of this posttranslational modification, determine structures of the trapped precyclization intermediate and oxidized postcyclization states, and identify unanticipated features critical to chromophore maturation. The protein architecture contains a dramatic approximately 80 degrees bend in the central helix, which focuses distortions at G67 to promote ring formation from amino acids S65, Y66, and G67. Significantly, these distortions eliminate potential helical hydrogen bonds that would otherwise have to be broken at an energetic cost

SUBMITTER: Barondeau DP 

PROVIDER: S-EPMC218721 | biostudies-literature | 2003 Oct

REPOSITORIES: biostudies-literature