Structural Basis for Conformational Dynamics of GTP-bound Ras Protein

• DOI: 10.1074/jbc.m110.125161
• Publication Date: 2010-05-18T03:13:53Z
• Authors: Fumi Shima; Yuichi Ijiri; Shin Muraoka; Jingling Liao; Min Ye; Mitsugu Araki; Kousuke Matsumoto; Naoki Yamamoto; Takeshi Sugimoto; Yoko Yoshikawa; Takashi Kumasaka; Masaki Yamamoto; Atsuo Tamura; Tohru Kataoka
• Keywords: Guanosine diphosphate; Conformational change

Ras family small GTPases assume two interconverting conformations, "inactive" state 1 and "active" 2, in their GTP-bound forms. Here, to clarify the mechanism of transition, we have carried out x-ray crystal structure analyses a series mutant H-Ras M-Ras complex with guanosine 5'-(beta,gamma-imido)triphosphate (GppNHp), representing various intermediate states transition. Crystallization H-RasT35S-GppNHp enables us solve first complete tertiary possessing surface pockets unseen 2 or H-Ras-GDP structure. Moreover, determination distinct structures H-RasT35S-GppNHp, showing prominent polysterism switch I II regions, reveals pivotal role guanine nucleotide-mediated interaction between regions its rearrangement by nucleotide positional change Furthermore, (31)P NMR spectra GppNHp-bound forms mutants, carrying H-Ras-type amino acid substitutions, also reveal existence pocket support similar based on Intriguingly, conformational changes accompanying transition mimic those that occurred upon GDP/GTP exchange, indicating common mechanistic basis inherent high flexibility regions. Collectively, these results structural features distinguishing provide new insights into molecular for protein.