Induced opening of conformational switch I in GTP-bound Ran GTPase.

ABSTRACT: Ran is a small GTPase that regulates nucleocytoplasmic transport by cycling between an inactive GDP-bound and active GTP-bound state. Structurally, Ran consists of a globular G-domain and a C-terminal region that includes a C-terminal helix. The switch I and II regions of the G-domain undergo major conformational changes upon GTP hydrolysis, with switch I shifting from a closed to an open conformation, regulating cargo loading/unloading. In this study, we describe an induced conformational change in RanGTP that drives switch I from its closed, active state (state 2) to a fully open, inactive state, resembling the RanGDP conformation. This transition is consistently triggered by disruption of two key interactions: Thr42-Mg²⁺ coordination (leading to state 1) and the Phe35-GTP-Lys

SUBMITTER: Czigleczki J 

PROVIDER: S-EPMC12903546 | biostudies-literature | 2026 Mar

REPOSITORIES: biostudies-literature