4ao5

B. subtilis prophage dUTPase YosS in complex with dUMP

spinqualitylabelsall models 4ao5, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4ao5 is a 6 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.6Å Ligands: NA, UMP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function YOSS_BACSU This enzyme is involved in nucleotide metabolism: it produces dUMP, the immediate precursor of thymidine nucleotides and it decreases the intracellular concentration of dUTP so that uracil cannot be incorporated into DNA. Publication Abstract from PubMed Homotrimeric dUTPases contain three active sites, each formed by five conserved sequence motifs originating from all three subunits. The essential fifth motif lies in a flexible C-terminal arm which becomes ordered during catalysis and is disordered in most crystal structures. Previously, it has been shown that the two Bacillus subtilis dUTPases, YncF and YosS, differ from their orthologues in the position in the sequence of the essential Phe-lid residue, which stacks against the uracil base, and in the conformation of the general base aspartate, which points away from the active site. Here, three structures of the complex of YncF with dU-PPi-Mg(2+) and the structure of YosS complexed with dUMP are reported. dU-PPi-Mg(2+) triggers the ordering of both the C-terminal arm and a loop (residues 18-26) which is uniquely disordered in the Bacillus dUTPases. The dUMP complex suggests two stages in substrate release. Limited proteolysis experiments allowed those complexes in which C-terminal cleavage is hindered and those in which it can be assumed to be ordered to be identified. The results lead to the suggestion that dUpNHpp is not a perfect substrate mimic, at least for the B. subtilis enzymes, and provide new insights into the mechanism of these two dUTPases in comparison to their orthologues. The enzyme mechanism is reviewed using the present and previous crystal structures as snapshots along the reaction coordinate. Tying down the arm in Bacillus dUTPase: structure and mechanism.,Garcia-Nafria J, Timm J, Harrison C, Turkenburg JP, Wilson KS Acta Crystallogr D Biol Crystallogr. 2013 Aug;69(Pt 8):1367-80. doi:, 10.1107/S090744491300735X. Epub 2013 Jul 13. PMID:23897460 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DUTPase 3D structures

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