Musacchio A, Saraste M, Wilmanns M
European Molecular Biology Laboratory, Heidelberg, Germany.
Nat Struct Biol. 1994 Aug;1(8):546-51. doi: 10.1038/nsb0894-546.
Src-homology 3 (SH3) domains bind to proline-rich motifs in target proteins. We have determined high-resolution crystal structures of the complexes between the SH3 domains of Abl and Fyn tyrosine kinases, and two ten-residue proline-rich peptides derived from the SH3-binding proteins 3BP-1 and 3BP-2. The X-ray data show that the basic mode of binding of both proline-rich peptides is the same. Peptides are bound over their entire length and interact with three major sites on the SH3 molecules by both hydrogen-bonding and van der Waals contacts. Residues 4-10 of the peptide adopt the conformation of a left-handed polyproline helix type II. Binding of the proline at position 2 requires a kink at the non-proline position 3.
Src同源结构域3（SH3）与靶蛋白中富含脯氨酸的基序结合。我们已经确定了Abl和Fyn酪氨酸激酶的SH3结构域与源自SH3结合蛋白3BP - 1和3BP - 2的两个十肽富含脯氨酸肽段之间复合物的高分辨率晶体结构。X射线数据表明，两种富含脯氨酸肽段的基本结合模式相同。肽段在其全长上结合，并通过氢键和范德华接触与SH3分子上的三个主要位点相互作用。肽段的第4 - 10位残基采用II型左手多聚脯氨酸螺旋构象。第2位脯氨酸的结合需要在非脯氨酸的第3位产生一个扭结。
