Multiple modes of peptide recognition by the PTB domain of the cell fate determinant Numb.Zwahlen, C., Li, S.C., Kay, L.E., Pawson, T., Forman-Kay, J.D.
(2000) EMBO J 19: 1505-1515
- PubMed: 10747019
- DOI: https://doi.org/10.1093/emboj/19.7.1505
- Primary Citation of Related Structures:
- PubMed Abstract:
The phosphotyrosine-binding (PTB) domain of the cell fate determinant Numb is involved in the formation of multiple protein complexes in vivo and can bind a diverse array of peptide sequences in vitro. To investigate the structural basis for the promiscuous nature of this protein module, we have determined its solution structure by NMR in a complex with a peptide containing an NMSF sequence derived from the Numb-associated kinase (Nak). The Nak peptide was found to adopt a significantly different structure from that of a GPpY sequence-containing peptide previously determined. In contrast to the helical turn adopted by the GPpY peptide, the Nak peptide forms a beta-turn at the NMSF site followed by another turn near the C-terminus. The Numb PTB domain appears to recognize peptides that differ in both primary and secondary structures by engaging various amounts of the binding surface of the protein. Our results suggest a mechanism through which a single PTB domain might interact with multiple distinct target proteins to control a complex biological process such as asymmetric cell division.
Structural Biology and Biochemistry Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8.