The 2.2 A crystal structure of transducin-alpha complexed with GTP gamma S

Nature. 1993 Dec 16;366(6456):654-63. doi: 10.1038/366654a0.


The 2.2 A crystal structure of activated rod transducin, Gt alpha.GTP gamma S, shows the bound GTP gamma S molecule occluded deep in a cleft between a domain structurally homologous to small GTPases and a helical domain unique to heterotrimeric G proteins. The structure, when combined with biochemical and genetic studies, suggests: how an activated receptor might open this cleft to allow nucleotide exchange; a mechanism for GTP-induced changes in effector and receptor binding surfaces; and a mechanism for GTPase activity not evident from previous data.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Catalysis
  • Cattle
  • Computer Graphics
  • Crystallography, X-Ray
  • Guanosine 5'-O-(3-Thiotriphosphate) / chemistry*
  • Guanosine 5'-O-(3-Thiotriphosphate) / metabolism
  • Guanosine Diphosphate / metabolism
  • Guanosine Triphosphate / metabolism
  • Hydrolysis
  • Models, Molecular
  • Molecular Sequence Data
  • Phosphoric Diester Hydrolases / metabolism
  • Protein Binding
  • Protein Conformation
  • Retinal Rod Photoreceptor Cells / chemistry
  • Rhodopsin / metabolism
  • Transducin / chemistry*
  • Transducin / metabolism


  • Guanosine Diphosphate
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • Guanosine Triphosphate
  • Rhodopsin
  • Phosphoric Diester Hydrolases
  • Transducin