1GDD

TERTIARY AND QUATERNARY STRUCTURAL CHANGES IN GIA1 INDUCED BY GTP HYDROLYSIS

Summary for 1GDD

• Entry DOI: 10.2210/pdb1gdd/pdb
• Descriptor: GI ALPHA 1, SULFATE ION, GUANOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: gtp-ase, signal transduction protein
• Biological source: Rattus norvegicus (Norway rat)
• Cellular location: Nucleus: P10824
• Total number of polymer chains: 1
• Total formula weight: 40807.10

Authors

Mixon, M.B.,Sprang, S.R. (deposition date: 1995-07-25, release date: 1995-11-27, Last modification date: 2024-02-07)

Primary citation

Mixon, M.B.,Lee, E.,Coleman, D.E.,Berghuis, A.M.,Gilman, A.G.,Sprang, S.R.
Tertiary and quaternary structural changes in Gi alpha 1 induced by GTP hydrolysis.
Science, 270:954-960, 1995

PubMed Abstract: 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.

PubMed: 7481799

Experimental method

X-RAY DIFFRACTION (2.2 Å)