Solution structure of the Grb2 N-terminal SH3 domain complexed with a ten-residue peptide derived from SOS: direct refinement against NOEs, J-couplings and ¹H and ¹³C chemical shifts

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• 作者：Wittekind ; Michael ; Mapelli ; Claudio ; Lee ; Ving ; Goldfarb ; Valentina ; Friedrichs ; Mark S. ; et. al.
• 关键词：NMR ; SH3 ; Grb2 ; poly-proline type II ; chemical shift ; SH3 ; src -homology domain 3 ; Grb2 ; growth factor receptor-binding protein 2 ; N-SH3 ; amino-terminal SH3 domain of Grb2 ; C-SH3 ; carboxy-terminal SH3 domain of Grb2 ; SOS-E ; ac-VPPPVPPRRR-nh2 peptide ; 2D
• 刊名：Journal of Molecular Biology
• 出版年：1997
• 出版时间：April 11, 1997
• 年：1997
• 卷：267
• 期：4
• 页码：933-952
• 全文大小：722 K

文摘

Refined ensembles of solution structures have been calculated for the N-terminal SH3 domain of Grb2 (N-SH3) complexed with the ac-VPPPVPPRRR-nh2 peptide derived from residues 1135 to 1144 of the mouse SOS-1 sequence. NMR spectra obtained from different combinations of both¹³C-¹⁵N-labeled and unlabeled N-SH3 and SOS peptide fragment were used to obtain stereo-assignments for pro-chiral groups of the peptide, angle restraints via heteronuclear coupling constants, and complete¹H,¹³C, and¹⁵N resonance assignments for both molecules. One ensemble of structures was calculated using conventional methods while a second ensemble was generated by including additional direct refinements against both¹H and¹³C^α/¹³C^βchemical shifts. In both ensembles, the protein:peptide interface is highly resolved, reflecting the inclusion of 110 inter-molecular nuclear Overhauser enhancement (NOE) distance restraints. The first and second peptide-binding sub-sites of N-SH3 interact with structurally well-defined portions of the peptide. These interactions include hydrogen bonds and extensive hydrophobic contacts. In the third highly acidic sub-site, the conformation of the peptide Arg8 side-chain is partially ordered by a set of NOE restraints to the Trp36 ring protons. Overall, several lines of evidence point to dynamical averaging of peptide and N-SH3 side-chain conformations in the third sub-site. These conformations are characterized by transient charge stabilized hydrogen bond interactions between the peptide arginine side-chain hydrogen bond donors and either single, or possibly multiple, acceptor(s) in the third peptide-binding sub-site.