2p4t

Structure of the Q67H mutant of R67 dihydrofolate reductase-NADP+ complex reveals a novel cofactor binding mode

spinqualitylabelsall models 2p4t, resolution 1.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2p4t is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.15Å Ligands: NAP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DYR21_ECOLX Key enzyme in folate metabolism. Catalyzes an essential reaction for de novo glycine and purine synthesis, and for DNA precursor synthesis. Publication Abstract from PubMed Plasmid-encoded bacterial R67 dihydrofolate reductase (DHFR) is a NADPH-dependent enzyme unrelated to chromosomal DHFR in amino acid sequence and structure. R67 DHFR is insensitive to the bacterial drug trimethoprim in contrast to chromosomal DHFR. The crystal structure of Q67H mutant of R67 DHFR bound to NADP(+) has been determined at 1.15 angstroms resolution. The cofactor assumes an extended conformation with the nicotinamide ring bound near the center of the active site pore, the ribose and pyrophosphate group (PP(i)) extending toward the outer pore. The ribonicotinamide exhibits anti conformation as in chromosomal DHFR complexes. The relative orientation between the PP(i) and the nicotinamide ribose differs from that observed in chromosomal DHFR-NADP(+) complexes. The coenzyme displays symmetrical binding mode with several water-mediated hydrogen bonds with the protein besides ionic, stacking, and van der Waals interactions. The structure provides a molecular basis for the observed stoichiometry and cooperativity in ligand binding. The ternary model based on the present structure and the previous R67 DHFR-folate complex provides insight into the catalytic mechanism and indicates that the relative orientation of the reactants in plasmid DHFR is different from that seen in chromosomal DHFRs. Structure of the Q67H mutant of R67 dihydrofolate reductase-NADP+ complex reveals a novel cofactor binding mode.,Divya N, Grifith E, Narayana N Protein Sci. 2007 Jun;16(6):1063-8. Epub 2007 May 1. PMID:17473013 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Dihydrofolate reductase 3D structures

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