Underlying Mechanism for Stimulated GMP Formation in a Unique Large GTPase hGBP1

Abstract

Unlike other GTPases, IFN-gamma inducible large GTPase human guanylate binding protein 1 (hGBP1) has a unique property of hydrolyzing GTP to both GDP and GMP through successive cleavages of the two phosphates. This protein is involved in immunity against several viruses. In the absence of the full-length hGBP1 structure with substrate in dimeric state, the mechanism of GTP hydrolysis was elucidated using the dimeric structure of truncated hGBP11-317(contains only catalytic domain) with various analogs.