Pin1 contains an N-terminal WW domain and a C-terminal peptidyl-prolyl cis-trans isomerase (PPIase) domain connected by a flexible linker. To address the energetic and structural basis for WW domain recognition of phosphoserine (P.Ser)/phosphothreonine (P. Thr)- proline containing proteins, we report the energetic and structural analysis of a Pin1-phosphopeptide complex. The X-ray crystal structure of Pin1 bound to a doubly phosphorylated peptide (Tyr-P.Ser-Pro-Thr-P.Ser-Pro-Ser) representing a heptad repeat of the RNA polymerase II large subunit's C-terminal domain (CTD), reveals the residues involved in the recognition of a single P.Ser side chain, the rings of two prolines, and the backbone of the CTD peptide. The side chains of neighboring Arg and Ser residues along with a backbone amide contribute to recognition of P.Ser. The lack of widespread conservation of the Arg and Ser residues responsible for P.Ser recognition in the WW domain family suggests that only a subset of WW domains can bind P.Ser-Pro in a similar fashion to that of Pin1.
Structural basis for phosphoserine-proline recognition by group IV WW domains.,Verdecia MA, Bowman ME, Lu KP, Hunter T, Noel JP Nat Struct Biol. 2000 Aug;7(8):639-43. PMID:10932246
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Verdecia MA, Bowman ME, Lu KP, Hunter T, Noel JP. Structural basis for phosphoserine-proline recognition by group IV WW domains. Nat Struct Biol. 2000 Aug;7(8):639-43. PMID:10932246 doi:10.1038/77929