1GIT

STRUCTURE OF GTP-BINDING PROTEIN

Summary for 1GIT

• Entry DOI: 10.2210/pdb1git/pdb
• Descriptor: G PROTEIN GI ALPHA 1, PHOSPHATE ION, GUANOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: gtp-ase, gtp-binding protein, transducer, adenylate cyclase, multigene family, myristylation
• Biological source: Rattus norvegicus (Norway rat)
• Cellular location: Nucleus: P10824
• Total number of polymer chains: 1
• Total formula weight: 40820.03

Authors

Berghuis, A.M.,Lee, E.,Sprang, S.R. (deposition date: 1996-10-16, release date: 1997-02-12, Last modification date: 2024-02-07)

Primary citation

Berghuis, A.M.,Lee, E.,Raw, A.S.,Gilman, A.G.,Sprang, S.R.
Structure of the GDP-Pi complex of Gly203-->Ala gialpha1: a mimic of the ternary product complex of galpha-catalyzed GTP hydrolysis.
Structure, 4:1277-1290, 1996

PubMed Abstract: G proteins play a vital role in transmembrane signalling events. In their inactive form G proteins exist as heterotrimers consisting of an alpha subunit, complexed with GDP and a dimer of betagamma subunits. Upon stimulation by receptors, G protein alpha subunits exchange GDP for GTP and dissociate from betagamma . Thus activated, alphasubunits stimulate or inhibit downstream effectors. The duration of the activated state corresponds to the single turnover rate of GTP hydrolysis, which is typically in the range of seconds. In Gialpha1, the Gly203-->Ala mutation reduces the affinity of the substrate for Mg2+, inhibits a key conformational step that occurs upon GTP binding and consequently inhibits the release of betagamma subunits from the GTP complex. The structure of the Gly203-->Ala mutant of Gialpha1 (G203AGialpha1) bound to the slowly hydrolyzing analog of GTP (GTPgammaS) has been determined in order to elucidate the structural changes that take place during hydrolysis.

PubMed: 8939752
DOI: 10.1016/S0969-2126(96)00136-0

Experimental method

X-RAY DIFFRACTION (2.6 Å)