4TS3
Wild type E. Coli purine nucleoside phosphorylase with 2 FMC molecules in active sites
Summary for 4TS3
| Entry DOI | 10.2210/pdb4ts3/pdb |
| Descriptor | Purine nucleoside phosphorylase DeoD-type, (1S)-1-(7-amino-1H-pyrazolo[4,3-d]pyrimidin-3-yl)-1,4-anhydro-D-ribitol, PHOSPHATE ION, ... (4 entities in total) |
| Functional Keywords | purine nucleoside phosphorylase, formycin a, transferase |
| Biological source | Escherichia coli |
| Total number of polymer chains | 6 |
| Total formula weight | 155434.11 |
| Authors | Stefanic, Z.,Bzowska, A. (deposition date: 2014-06-18, release date: 2015-07-08, Last modification date: 2024-05-08) |
| Primary citation | Stefanic, Z.,Narczyk, M.,Mikleusevic, G.,Kazazic, S.,Bzowska, A.,Luic, M. Crystallographic snapshots of ligand binding to hexameric purine nucleoside phosphorylase and kinetic studies give insight into the mechanism of catalysis. Sci Rep, 8:15427-15427, 2018 Cited by PubMed Abstract: Purine nucleoside phosphorylase (PNP) catalyses the cleavage of the glycosidic bond of purine nucleosides using phosphate instead of water as a second substrate. PNP from Escherichia coli is a homohexamer, build as a trimer of dimers, and each subunit can be in two conformations, open or closed. This conformational change is induced by the presence of phosphate substrate, and very likely a required step for the catalysis. Closing one active site strongly affects the others, by a yet unclear mechanism and order of events. Kinetic and ligand binding studies show strong negative cooperativity between subunits. Here, for the first time, we managed to monitor the sequence of nucleoside binding to individual subunits in the crystal structures of the wild-type enzyme, showing that first the closed sites, not the open ones, are occupied by the nucleoside. However, two mutations within the active site, Asp204Ala/Arg217Ala, are enough not only to significantly reduce the effectiveness of the enzyme, but also reverse the sequence of the nucleoside binding. In the mutant the open sites, neighbours in a dimer of those in the closed conformation, are occupied as first. This demonstrates how important for the effective catalysis of Escherichia coli PNP is proper subunit cooperation. PubMed: 30337572DOI: 10.1038/s41598-018-33723-1 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.3 Å) |
Structure validation
Download full validation report
