Interaction of class A G protein-coupled receptors with G proteins

Acta Biochim Pol. 2004;51(1):129-36.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Binding Sites
  • Conserved Sequence
  • Darkness
  • Drug Stability
  • GTP-Binding Proteins / chemistry
  • GTP-Binding Proteins / metabolism
  • Membrane Proteins / chemistry
  • Models, Molecular
  • Protein Conformation
  • Receptors, G-Protein-Coupled / chemistry*
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism*
  • Retinaldehyde / metabolism
  • Rhodopsin / chemistry*
  • Rhodopsin / genetics
  • Static Electricity
  • Transducin / chemistry*
  • Transducin / genetics

Substances

  • Membrane Proteins
  • Receptors, G-Protein-Coupled
  • Rhodopsin
  • GTP-Binding Proteins
  • Transducin
  • Retinaldehyde