2fll

Ternary complex of human DNA polymerase iota with DNA and dTTP

spinqualitylabelsall models 2fll, resolution 2.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2fll is a 3 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.6Å Ligands: DOC, MG, TTP 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 Substrate-induced conformational change of the protein is the linchpin of enzymatic reactions. Replicative DNA polymerases, for example, convert from an open to a closed conformation in response to dNTP binding. Human DNA polymerase-iota (hPoliota), a member of the Y family of DNA polymerases, differs strikingly from other polymerases in its much higher proficiency and fidelity for nucleotide incorporation opposite template purines than opposite template pyrimidines. We present here a crystallographic analysis of hPoliota binary complexes, which together with the ternary complexes show that, contrary to replicative DNA polymerases, the DNA, and not the polymerase, undergoes the primary substrate-induced conformational change. The incoming dNTP "pushes" templates A and G from the anti to the syn conformation dictated by a rigid hPoliota active site. Together, the structures posit a mechanism for template selection wherein dNTP binding induces a conformational switch in template purines for productive Hoogsteen base pairing. An incoming nucleotide imposes an anti to syn conformational change on the templating purine in the human DNA polymerase-iota active site.,Nair DT, Johnson RE, Prakash L, Prakash S, Aggarwal AK Structure. 2006 Apr;14(4):749-55. PMID:16615915 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase 3D structures

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