3lzi | pdb_00003lzi

RB69 DNA Polymerase (Y567A) ternary complex with dATP Opposite 7,8-dihydro-8-oxoguanine

spinqualitylabelsall models 3lzi, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3lzi is a 3 chain structure with sequence from Escherichia phage RB69. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.3Å Ligands: 8OG, CA, DOC, DTP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DPOL_BPR69 This polymerase possesses two enzymatic activities: DNA synthesis (polymerase) and an exonucleolytic activity that degrades single stranded DNA in the 3'- to 5'-direction. 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 Accurate copying of the genome by DNA polymerases is challenging due in part to the continuous damage inflicted on DNA, which results from its contact with reactive oxygen species (ROS), producing lesions such as 7,8-dihydro-8-oxoguanine (8-oxoG). The deleterious effects of 8-oxoG can be attributed to its dual coding potential that leads to G --> T transversions. The wild-type (wt) pol alpha family DNA polymerase from bacteriophage RB69 (RB69pol) prefers to insert dCMP as opposed to dAMP when situated opposite 8-oxoG by >2 orders of magnitude as demonstrated using pre-steady-state kinetics (k(pol)/K(d,app)). In contrast, the Y567A mutant of RB69pol inserts both dCMP and dAMP opposite 8-oxoG rapidly and with equal efficiency. We have determined the structures of preinsertion complexes for the Y567A mutant with dATP and dCTP opposite a templating 8-oxoG in a 13/18mer primer-template (P/T) at resolutions of 2.3 and 2.1 A, respectively. Our structures show that the 8-oxoG residue is in the anti conformation when paired opposite dCTP, but it flips to a syn conformation forming a Hoogstein base pair with an incoming dATP. Although the Y567A substitution does not significantly change the volume of the pocket occupied by anti-8-oxoG, it does provide residue G568 the flexibility to move deeper into the minor groove of the P/T to accommodate, and stabilize, syn-8-oxoG. These results support the hypothesis that it is the flexibility of the nascent base pair binding pocket (NBP) in the Y567A mutant that allows efficient insertion of dAMP opposite 8-oxoG. Substitution of Ala for Tyr567 in RB69 DNA polymerase allows dAMP to be inserted opposite 7,8-dihydro-8-oxoguanine .,Beckman J, Wang M, Blaha G, Wang J, Konigsberg WH Biochemistry. 2010 May 18;49(19):4116-25. PMID:20411947 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase 3D structures

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