1bd3

STRUCTURE OF THE APO URACIL PHOSPHORIBOSYLTRANSFERASE, 2 MUTANT C128V

spinqualitylabelsall models 1bd3, resolution 1.93Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1bd3 is a 4 chain structure with sequence from Toxoplasma gondii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: PO4 Activity: Uracil phosphoribosyltransferase, with EC number 2.4.2.9 Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Uracil phosphoribosyltransferase (UPRTase) catalyzes the transfer of a ribosyl phosphate group from alpha-D-5-phosphoribosyl-1-pyrophosphate to the N1 nitrogen of uracil. The UPRTase from the opportunistic pathogen Toxoplasma gondii is a rational target for antiparasitic drug design. To aid in structure-based drug design studies against toxoplasmosis, the crystal structures of the T.gondii apo UPRTase (1.93 A resolution), the UPRTase bound to its substrate, uracil (2.2 A resolution), its product, UMP (2.5 A resolution), and the prodrug, 5-fluorouracil (2.3 A resolution), have been determined. These structures reveal that UPRTase recognizes uracil through polypeptide backbone hydrogen bonds to the uracil exocyclic O2 and endocyclic N3 atoms and a backbone-water-exocyclic O4 oxygen hydrogen bond. This stereochemical arrangement and the architecture of the uracil-binding pocket reveal why cytosine and pyrimidines with exocyclic substituents at ring position 5 larger than fluorine, including thymine, cannot bind to the enzyme. Strikingly, the T. gondii UPRTase contains a 22 residue insertion within the conserved PRTase fold that forms an extended antiparallel beta-arm. Leu92, at the tip of this arm, functions to cap the active site of its dimer mate, thereby inhibiting the escape of the substrate-binding water molecule. Crystal structures of Toxoplasma gondii uracil phosphoribosyltransferase reveal the atomic basis of pyrimidine discrimination and prodrug binding.,Schumacher MA, Carter D, Scott DM, Roos DS, Ullman B, Brennan RG EMBO J. 1998 Jun 15;17(12):3219-32. PMID:9628859 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phosphoribosyltransferase

Proteopedia Page Contributors and Editors (what is this?)

OCA