The crystal structure of pyrimidine nucleoside phosphorylase in a closed conformation.
Pugmire, M.J., Ealick, S.E.(1998) Structure 6: 1467-1479
- PubMed: 9817849 
- DOI: https://doi.org/10.1016/s0969-2126(98)00145-2
- Primary Citation of Related Structures:  
1BRW - PubMed Abstract: 
Pyrimidine nucleoside phosphorylase (PYNP) catalyzes the reversible phosphorolysis of pyrimidines in the nucleotide synthesis salvage pathway. In lower organisms (e.g. Bacillus stearothermophilus) PYNP accepts both thymidine and uridine, whereas in mammalian and other higher organisms it is specific for thymidine (designated thymidine phosphorylase, TP). PYNP shares 40% sequence similarity (and presumably significant structural similarity) with human TP, which has been implicated as a growth factor in tumor angiogenesis. It is thought that TP undergoes a major conformational change upon substrate binding that consequently produces an active conformation.
Organizational Affiliation: 
Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853, USA.