Structural basis for phosphoserine-proline recognition by group IV WW domains.
Verdecia, M.A., Bowman, M.E., Lu, K.P., Hunter, T., Noel, J.P.(2000) Nat Struct Biol 7: 639-643
- PubMed: 10932246 
- DOI: https://doi.org/10.1038/77929
- Primary Citation of Related Structures:  
1F8A - PubMed Abstract: 
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.
Organizational Affiliation: 
Structural Biology Laboratory, University of California, San Diego, La Jolla, California 92093, USA.