3g6y

Ternary complex of DNA Polymerase iota:DNA:dTTP with an abasic site at the templating position

spinqualitylabelsall models 3g6y, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3g6y is a 3 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: MG, TTP NonStd Res: 3DR, DOC Related: 2fll, 3g6v, 3g6x Gene: POLI, RAD30B (HUMAN) Activity: DNA-directed DNA polymerase, with EC number 2.7.7.7 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [POLI_HUMAN] Error-prone DNA polymerase specifically involved in DNA repair. Plays an important role in translesion synthesis, where the normal high-fidelity DNA polymerases cannot proceed and DNA synthesis stalls. Favors Hoogsteen base-pairing in the active site. Inserts the correct base with high-fidelity opposite an adenosine template. Exhibits low fidelity and efficiency opposite a thymidine template, where it will preferentially insert guanosine. May play a role in hypermutation of immunogobulin genes. Forms a Schiff base with 5'-deoxyribose phosphate at abasic sites, but may not have lyase activity. 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 Abasic sites are among the most abundant DNA lesions formed in human cells, and they present a strong block to replication. DNA polymerase iota (Poliota) is one of the few DNA Pols that does not follow the A-rule opposite an abasic site. We present here three structures of human Poliota in complex with DNAs containing an abasic lesion and dGTP, dTTP, or dATP as the incoming nucleotide. The structures reveal a mechanism of translesion synthesis across an abasic lesion that differs from that in other Pols. Both the abasic lesion and the incoming dNTPs are intrahelical and are closely apposed across a constricted active site cleft. The dNTPs partake in distinct networks of hydrogen bonds in the "void" opposite the lesion. These different patterns of hydrogen bonds, as well as stacking interactions, may underlie Poliota's small preference for insertion of dGTP over other nucleotides opposite this common lesion. DNA synthesis across an abasic lesion by human DNA polymerase iota.,Nair DT, Johnson RE, Prakash L, Prakash S, Aggarwal AK Structure. 2009 Apr 15;17(4):530-7. PMID:19368886 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase 3D structures

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