Gt-protein or transducin

Function: - second messengers relaying signals from G-protein-coupled receptors (serpentine receptors) - couples rhodopsin with cGMP phosphodiesterase Structure: - Gt-alpha - G-beta/gamma - GDP/GTP complex

General

G-protein oligomerizing protein

Properties

SUBUNITS: Gt-alpha MOTIF: binding site EFFECTOR-BOUND: G-beta/gamma P-loop EFFECTOR-BOUND: guanosine triphosphate Mg+2-binding site Ser phosphorylation site ADP-ribosylation site {C350} guanine nucleotide-binding site EFFECTOR-BOUND: guanosine diphosphate ADP-ribosylation site GTP-binding regulatory protein beta MOTIF: WD repeat (8) membrane region Ser phosphorylation site GTP-binding regulatory protein gamma-1 MOTIF: cysteine residue {C36} MODIFICATION: cysteine residue {C37} cysteine residue {C37} MODIFICATION: cysteine residue {C36} CaaX motif SITE: C-TERMINUS QUALITIES: AAX-TRUNCATED CARBOXYMETHYLATED EFFECTOR-BOUND: farnesyl BOUND-VIA: cysteine residue COMPARTMENT: plasma membrane* CELL: photoreceptor cell WITHIN: retina ORGANISM: mammal* MOTIF: Mg+2-binding site

References

- Bourne HR et al, The GTPase superfamily: a conserved switch for diverse cell functions Nature 348:125 1990 PMID: 2122258

Components

Gt-alpha GTP-binding regulatory protein beta guanine nucleotide binding protein (G protein), gamma 1; GTP-binding regulatory protein gamma-1; transducin gamma chain (GNGT1)