Critical roles of interactions among switch I-preceding residues and between switch II and its neighboring alpha-helix in conformational dynamics of the GTP-bound Ras family small GTPases.

ABSTRACT: GTP-bound forms of Ras family small GTPases exhibit dynamic equilibrium between two interconverting conformations, "inactive" state 1 and "active" state 2. A great variation exists in their state distribution; H-Ras mainly adopts state 2, whereas M-Ras predominantly adopts state 1. Our previous studies based on comparison of crystal structures representing state 1 and state 2 revealed the importance of the hydrogen-bonding interactions of two flexible effector-interacting regions, switch I and switch II, with the γ-phosphate of GTP in establishing state 2 conformation. However, failure to obtain both state structures from a single protein hampered further analysis of state transition mechanisms. Here, we succeed in solving two crystal structures corresponding to state 1 and state 2 from a

SUBMITTER: Matsumoto K 

PROVIDER: S-EPMC3083163 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature