NMR analysis of interactions of a phosphatidylinositol 3'-kinase SH2 domain with phosphotyrosine peptides reveals interdependence of major binding sites

Biochemistry
Ulrich L GüntherBrian Schaffhausen

Abstract

The interactions of the N-terminal src homology (SH2) domain (N-SH2) of the 85 kDa subunit of phosphatidylinositol 3'-kinase (PI-3K) with phosphotyrosine (ptyr) and a series of ptyr-containing peptides have been examined by NMR spectroscopy. HSQC (heteronuclear single-quantum coherence) NMR spectra of 15N-labeled SH2 were used to evaluate its interactions with ptyr-containing ligands. The ability of ligands to cause chemical shift changes was compared to their potency as competitors in in vitro binding experiments using polyoma virus middle T antigen (MT). The results suggest the interdependence of SH2 binding elements. Chemical shifts of residues involved in the ptyr binding were altered by variations of the sequence of the bound peptide, suggesting that the ptyr fit can be adjusted by the peptide sequence. Perturbations of chemical shifts of residues coordinating the methionine three residues C-terminal to the ptyr (the +3 residue) were affected by substitution in the binding peptide at +1 and vice versa. Such results show synergistic interplay between regions of the SH2 binding residues C-terminal to the ptyr.

Citations

Mar 12, 2003·Proceedings of the National Academy of Sciences of the United States of America·Zheng FuGary J Gerfen
Jun 4, 2005·The Journal of Biological Chemistry·S Chandra ShekarJonathan M Backer
Jul 11, 2020·Journal of Structural Biology: X·Michelangelo Marasco, Teresa Carlomagno
Jul 30, 2014·Proteome Science·Michael HöfenerNorbert Sewald
Jul 22, 2004·Journal of the American Chemical Society·Tanja MittagUlrich L Günther

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