ยท
G. Waksman, S.E. Shoelson, N. Pant, D. Cowburn, and J. Kuriyan.
Binding of a high affinity phosphotyrosyl peptide to the Src SH2 domain:
crystal structures of the complexed and peptide-free forms.
Cell. 72:779-790.
(1992)
The crystal structure of the Src SH2
domain complexed with a high affinity 11-residue phosphopeptide has been
determined at 2.7 A resolution by X-ray diffraction. The peptide binds in an
extended conformation and makes primary interactions with the SH2 domain at six
central residues: PQ(pY)EEI. The phosphotyrosine and the isoleucine are tightly
bound by two well-defined pockets on the protein surface, resulting in a
complex that resembles a two-pronged plug engaging a two-holed socket. The
glutamate residues are in solvent-exposed environments in the vicinity of basic
side chains of the SH2 domain, and the two N-terminal residues cap the
phosphotyrosine-binding site. The crystal structure of Src SH2 in the absence
of peptide has been determined at 2.5 A resolution, and comparison with the
structure of the high affinity complex reveals only localized and relatively
small changes.
