Tyrosine kinase phosphorylation
Substrates of tyrosine protein kinases are generally characterized by a lysine or an arginine seven residues to the N-terminal side of the phosphorylated tyrosine. An acidic residue (Asp or Glu) is often found at either three or four residues to the N-terminal side of the tyrosine.
There are a number of exceptions to this rule such as the tyrosine phosphorylation sites of enolase and lipocortin II. We developed two signature patterns for the tyrosine kinase phosphorylation sites. The first pattern is directed against the sites where the acidic residue (Asp or Glu) is found at three residues to the N-terminal side of the tyrosine, and the second one against the site where it is at four.