1mq2

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Revision as of 16:07, 12 November 2007

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spinqualitylabelsall models 1mq2, resolution 3.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Human DNA Polymerase Beta Complexed With Gapped DNA Containing an 8-oxo-7,8-dihydro-Guanine and dAMP

Overview

Oxidative damage to DNA generates 8-oxo-7,8-dihydro-2'-deoxyguanosine, (8-oxodG). During DNA replication and repair synthesis, 8-oxodG can pair, with cytosine or adenine. The ability to accurately replicate through this, lesion depends on the DNA polymerase. We report the first structure of a, polymerase with a promutagenic DNA lesion, 8-oxodG, in the confines of its, active site. The modified guanine residue is in an anti conformation and, forms Watson-Crick hydrogen bonds with an incoming dCTP. To accommodate, the oxygen at C8, the 5'-phosphate backbone of the templating nucleotide, flips 180 degrees. Thus, the flexibility of the template sugar-phosphate, backbone near the polymerase active site is one parameter that influences, the anti-syn equilibrium of 8-oxodG. Our results provide insights into the, mechanisms employed by polymerases to select the complementary dNTP.

About this Structure

1MQ2 is a Single protein structure of sequence from Homo sapiens with NA and DA as ligands. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Full crystallographic information is available from OCA.

Reference

Structure of DNA polymerase beta with the mutagenic DNA lesion 8-oxodeoxyguanine reveals structural insights into its coding potential., Krahn JM, Beard WA, Miller H, Grollman AP, Wilson SH, Structure. 2003 Jan;11(1):121-7. PMID:12517346

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