MOLECULAR-BASIS FOR INTERACTION OF THE PROTEIN-TYROSINE KINASE ZAP-70WITH THE T-CELL RECEPTOR

The crystal structure of the tandem SH2 domains of human ZAP-70 in com plex with a peptide derived from the zeta-subunit of the T-cell recept or reveals an unanticipated interaction between the two domains. A coi led coil of a-helices connects the two SH2 domains, producing apr inte rface that constitutes one of the two critical phosphotyrosine binding sites. These and other unique features provide the molecular basis fo r highly selective association of ZAP-70 with the T-cell receptor.