Interaction of class A G protein-coupled receptors with G proteins.
A model for interaction of class A G protein-coupled receptor with the G protein G(alpha) subunit is proposed using the rhodopsin-transducin (RD/Gt) prototype. The model combines the resolved interactions/distances, essential in the active RD*/Gt system, with the structure of Gt(alpha) C-terminal peptide bound to RD* while stabilizing it. Assuming the interactions involve conserved parts of the partners, the model specifies the conserved Helix 2 non-polar X- - -X, Helix 3 DRY and Helix 7/8 NP- -Y- - F RD* motifs interacting with the Gt(alpha) C-terminal peptide, in compliance with the structure of the latter. A concomitant role of Gt(alpha) and Gt(gamma) C-termini in stabilizing RD* could possibly be resolved assuming a receptor dimer as requisite for G protein activation.
Slusarz
Rafał
R
Faculty of Chemistry, University of Gdansk, Gdańsk, Poland.
Ciarkowski
Jerzy
J
D019943:Amino Acid Substitution; D001665:Binding Sites; D017124:Conserved Sequence; D003624:Darkness; D004355:Drug Stability; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012172:Retinaldehyde / Q000378:metabolism; D012243:Rhodopsin / Q000737:chemistry* / Q000235:genetics; D055672:Static Electricity; D015293:Transducin / Q000737:chemistry* / Q000235:genetics
D008565:Membrane Proteins; D043562:Receptors, G-Protein-Coupled; D012243:Rhodopsin; D019204:GTP-Binding Proteins; D015293:Transducin; D012172:Retinaldehyde