6U6B

Structure of human DNA polymerase beta misinserting dAMPNPP opposite the 5'G of the cisplatin Pt-GG intrastrand crosslink with Manganese in the active site

6U6B の概要

• エントリーDOI: 10.2210/pdb6u6b/pdb
• 関連するPDBエントリー: 6U2O
• 分子名称: DNA polymerase beta, DNA (5'-D(*CP*CP*CP*AP*CP*GP*GP*CP*CP*CP*AP*TP*CP*AP*CP*C)-3'), DNA (5'-D(P*GP*GP*TP*GP*AP*TP*GP*GP*GP*C)-3'), ... (9 entities in total)
• 機能のキーワード: polymerase, cisplatin, mismatch, pt-gg, transferase, transferase-dna complex, transferase/dna
• 由来する生物種: Homo sapiens (Human); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 48653.97

構造登録者

Ouzon-Shubeita, H.,Vilas, C.K.,Lee, S. (登録日: 2019-08-29, 公開日: 2020-09-09, 最終更新日: 2023-10-11)

主引用文献

Ouzon-Shubeita, H.,Vilas, C.K.,Lee, S.
Structural insights into the promutagenic bypass of the major cisplatin-induced DNA lesion.
Biochem.J., 477:937-951, 2020

PubMed Abstract: The cisplatin-1,2-d(GpG) (Pt-GG) intrastrand cross-link is the predominant DNA lesion generated by cisplatin. Cisplatin has been shown to predominantly induce G to T mutations and Pt-GG permits significant misincorporation of dATP by human DNA polymerase β (polβ). In agreement, polβ overexpression, which is frequently observed in cancer cells, is linked to cisplatin resistance and a mutator phenotype. However, the structural basis for the misincorporation of dATP opposite Pt-GG is unknown. Here, we report the first structures of a DNA polymerase inaccurately bypassing Pt-GG. We solved two structures of polβ misincorporating dATP opposite the 5'-dG of Pt-GG in the presence of Mg2+ or Mn2+. The Mg2+-bound structure exhibits a sub-optimal conformation for catalysis, while the Mn2+-bound structure is in a catalytically more favorable semi-closed conformation. In both structures, dATP does not form a coplanar base pairing with Pt-GG. In the polβ active site, the syn-dATP opposite Pt-GG appears to be stabilized by protein templating and pi stacking interactions, which resembles the polβ-mediated dATP incorporation opposite an abasic site. Overall, our results suggest that the templating Pt-GG in the polβ active site behaves like an abasic site, promoting the insertion of dATP in a non-instructional manner.

PubMed: 32039434
DOI: 10.1042/BCJ20190906

実験手法

X-RAY DIFFRACTION (3.108 Å)