Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-4 precursor, also known as GNG4, is members of a multigene family and are implicated in determining the specificity of receptor-G protein interaction. In mammals, G protein alpha, beta and gamma polypeptides are encoded by at least 16, 4 and 7 genes, respectively. GNG4 is becoming increasingly clear that different G protein complexes expressed in different tissues carry structurally distinct members of the gamma as well as the alpha and beta subunits and that preferential association between members of subunit families increase G protein functional diversity. Recombinant human GNG4 protein, fused to His-tag at N-terminus, was expressed in E.coli.