4x0q | pdb_00004x0q

Ternary complex of human DNA polymerase theta C-terminal domain binding ddGTP opposite dCMP

spinqualitylabelsall models 4x0q, resolution 3.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4x0q is a 6 chain structure with sequence from Homo sapiens and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.9Å Ligands: DG3, GOL, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DPOLQ_HUMAN Has a DNA polymerase activity on nicked double-stranded DNA and on a singly primed DNA template. The enzyme activity is resistant to aphidicolin, and inhibited by dideoxynucleotides. Exhibites a single-stranded DNA-dependent ATPase activity. Could be involved in the repair of interstrand cross-links. Publication Abstract from PubMed DNA polymerase theta protects against genomic instability via an alternative end-joining repair pathway for DNA double-strand breaks. Polymerase theta is overexpressed in breast, lung and oral cancers, and reduction of its activity in mammalian cells increases sensitivity to double-strand break-inducing agents, including ionizing radiation. Reported here are crystal structures of the C-terminal polymerase domain from human polymerase theta, illustrating two potential modes of dimerization. One structure depicts insertion of ddATP opposite an abasic-site analog during translesion DNA synthesis. The second structure describes a cognate ddGTP complex. Polymerase theta uses a specialized thumb subdomain to establish unique upstream contacts to the primer DNA strand, including an interaction with the 3'-terminal phosphate from one of five distinctive insertion loops. These observations demonstrate how polymerase theta grasps the primer to bypass DNA lesions or extend poorly annealed DNA termini to mediate end-joining. Human DNA polymerase theta grasps the primer terminus to mediate DNA repair.,Zahn KE, Averill AM, Aller P, Wood RD, Doublie S Nat Struct Mol Biol. 2015 Mar 16. doi: 10.1038/nsmb.2993. PMID:25775267 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase 3D structures

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