1TK5

T7 DNA polymerase binary complex with 8 oxo guanosine in the templating strand

1TK5 の概要

• エントリーDOI: 10.2210/pdb1tk5/pdb
• 関連するPDBエントリー: 1T8E 1TK0
• 分子名称: 5'-D(*CP*GP*AP*AP*A*GP*CP*CP*AP*GP*TP*GP*CP*CP*AP*(DDG)P*TP*GP*CP*AP*A)-3', 5'-D(*CP*CP*CP*(8OG)P*CP*TP*GP*GP*CP*AP*CP*TP*GP*GP*CP*CP*GP*TP*CP*GP*TP*TP*TP*TP*CP*G)-3', DNA polymerase, ... (9 entities in total)
• 機能のキーワード: 8-oxoguanosine dna polymerase, transferase-electron transport-dna complex, transferase/electron transport/dna
• 由来する生物種: Enterobacteria phage T7; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 106130.58

構造登録者

Brieba, L.G.,Eichman, B.F.,Kokoska, R.J.,Doublie, S.,Kunkel, T.A.,Ellenberger, T. (登録日: 2004-06-08, 公開日: 2004-08-31, 最終更新日: 2023-08-23)

主引用文献

Brieba, L.G.,Eichman, B.F.,Kokoska, R.J.,Doublie, S.,Kunkel, T.A.,Ellenberger, T.
Structural basis for the dual coding potential of 8-oxoguanosine by a high-fidelity DNA polymerase.
Embo J., 23:3452-3461, 2004

PubMed Abstract: Accurate DNA replication involves polymerases with high nucleotide selectivity and proofreading activity. We show here why both fidelity mechanisms fail when normally accurate T7 DNA polymerase bypasses the common oxidative lesion 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8oG). The crystal structure of the polymerase with 8oG templating dC insertion shows that the O8 oxygen is tolerated by strong kinking of the DNA template. A model of a corresponding structure with dATP predicts steric and electrostatic clashes that would reduce but not eliminate insertion of dA. The structure of a postinsertional complex shows 8oG(syn).dA (anti) in a Hoogsteen-like base pair at the 3' terminus, and polymerase interactions with the minor groove surface of the mismatch that mimic those with undamaged, matched base pairs. This explains why translesion synthesis is permitted without proofreading of an 8oG.dA mismatch, thus providing insight into the high mutagenic potential of 8oG.

PubMed: 15297882
DOI: 10.1038/sj.emboj.7600354

実験手法

X-RAY DIFFRACTION (2.2 Å)