1gdd
TERTIARY AND QUATERNARY STRUCTURAL CHANGES IN GIA1 INDUCED BY GTP HYDROLYSIS
OverviewOverview
Crystallographic analysis of 2.2 angstrom resolution shows that guanosine triphosphate (GTP) hydrolysis triggers conformational changes in the heterotrimeric G-protein alpha subunit, Gi alpha 1. The switch II and switch III segments become disordered, and linker II connecting the Ras and alpha helical domains moves, thus altering the structures of potential effector and beta gamma binding regions. Contacts between the alpha-helical and Ras domains are weakened, possibly facilitating the release of guanosine diphosphate (GDP). The amino and carboxyl termini, which contain receptor and beta gamma binding determinants, are disordered in the complex with GTP, but are organized into a compact microdomain on GDP hydrolysis. The amino terminus also forms extensive quaternary contacts with neighboring alpha subunits in the lattice, suggesting that multimers of alpha subunits or heterotrimers may play a role in signal transduction.
About this StructureAbout this Structure
1GDD is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
Tertiary and quaternary structural changes in Gi alpha 1 induced by GTP hydrolysis., Mixon MB, Lee E, Coleman DE, Berghuis AM, Gilman AG, Sprang SR, Science. 1995 Nov 10;270(5238):954-60. PMID:7481799 Page seeded by OCA on Fri May 2 17:26:24 2008