Srinivasan V, Waterfield M D, Blundell T L
ICRF Unit of Structural Molecular Biology, Department of Crystallography, Birkbeck College, University of London, United Kingdom.
Biochem Biophys Res Commun. 1996 Mar 27;220(3):697-702. doi: 10.1006/bbrc.1996.0467.
Some of the pleckstrin homology (PH) domains are shown to bind beta gamma-subunits of a G-protein. In this paper we present a detailed comparison of sequences and structural features of beta gamma-binding regions in PH domains and alpha-subunits (G alpha) of known structure. Our comparison involves switch II region in G alpha and a C-terminal region of PH domain structures and we suggest a similarity in these regions. By comparing the active and inactive forms of G alpha structures we predict that some of the bulky hydrophobic residues in switch II region might interact with beta gamma-subunits. Subsequent to completion of this work we find that this prediction is absolutely consistent with recently reported crystal structures of heterotrimeric G-proteins. We discuss the feasibility of common principles in the recognition G alpha and PH domains by beta gamma-subunits.
一些普列克底物蛋白同源（PH）结构域被证明可与G蛋白的βγ亚基结合。在本文中，我们对已知结构的PH结构域和α亚基（Gα）中βγ结合区域的序列和结构特征进行了详细比较。我们的比较涉及Gα中的开关II区域和PH结构域结构的C末端区域，并且我们认为这些区域存在相似性。通过比较Gα结构的活性和非活性形式，我们预测开关II区域中的一些大的疏水残基可能与βγ亚基相互作用。在这项工作完成之后，我们发现这一预测与最近报道的异源三聚体G蛋白的晶体结构完全一致。我们讨论了βγ亚基识别Gα和PH结构域的共同原理的可行性。
