# YXXP Motif

National Cancer Institute

## Source

National Cancer Institute. *YXXP Motif*. NCI Thesaurus. Code C14059.

YXXP (tyrosine-X-X-Proline), a substrate sequence preferred by Abl tyrosine kinases, is part of the SH2 domain that mediates certain interactions of SH2 containing proteins. Although both phosphorylated- and unphosphorylated-YXXP can interacts with SH2 containing proteins, the SH2 domain obtain sufficient binding specificity from the recognition of adjacent residues to allow discrimination between different phosphorylated sites. (NCI)