... aresubtle, the phosphotyrosine at the +2 plays an impor-tant role in reordering the structure of the region of the C-terminal lobe that interacts with these substrates.In the absence of the phosphate ... shows clear density for most of the substrate pep-tide, including main chain atoms for the )4 through to the +4 position, but partial or no density for the sidechains of the N-terminal three ... comprised of residues Arg712 and the regionincluding residues Arg823–Asn830, whereas the OPT-YF peptide does not; therefore, the loss of the interac-tion with Asn830 would be more significant for the OPTYF...