4XUS

Crystal structure of the pre-catalytic ternary complex of DNA polymerase lambda with a templating A and an incoming dTTP

4XUS の概要

• エントリーDOI: 10.2210/pdb4xus/pdb
• 分子名称: DNA polymerase lambda, DNA (5'-D(P*GP*CP*CP*G)-3'), DNA (5'-D(*CP*AP*GP*TP*A)-3'), ... (8 entities in total)
• 機能のキーワード: dna polymerase lambda, protein-dna complex, helix-hairpin-helix, transferase-dna complex, transferase/dna
• 由来する生物種: Homo sapiens (Human); 詳細
• 細胞内の位置: Nucleus: Q9UGP5
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 43340.63

構造登録者

Burak, M.J.,Guja, K.E.,Garcia-Diaz, M. (登録日: 2015-01-26, 公開日: 2016-02-03, 最終更新日: 2024-02-28)

主引用文献

Burak, M.J.,Guja, K.E.,Garcia-Diaz, M.
Nucleotide binding interactions modulate dNTP selectivity and facilitate 8-oxo-dGTP incorporation by DNA polymerase lambda.
Nucleic Acids Res., 43:8089-8099, 2015

PubMed Abstract: 8-Oxo-7,8,-dihydro-2'-deoxyguanosine triphosphate (8-oxo-dGTP) is a major product of oxidative damage in the nucleotide pool. It is capable of mispairing with adenosine (dA), resulting in futile, mutagenic cycles of base excision repair. Therefore, it is critical that DNA polymerases discriminate against 8-oxo-dGTP at the insertion step. Because of its roles in oxidative DNA damage repair and non-homologous end joining, DNA polymerase lambda (Pol λ) may frequently encounter 8-oxo-dGTP. Here, we have studied the mechanisms of 8-oxo-dGMP incorporation and discrimination by Pol λ. We have solved high resolution crystal structures showing how Pol λ accommodates 8-oxo-dGTP in its active site. The structures indicate that when mispaired with dA, the oxidized nucleotide assumes the mutagenic syn-conformation, and is stabilized by multiple interactions. Steady-state kinetics reveal that two residues lining the dNTP binding pocket, Ala(510) and Asn(513), play differential roles in dNTP selectivity. Specifically, Ala(510) and Asn(513) facilitate incorporation of 8-oxo-dGMP opposite dA and dC, respectively. These residues also modulate the balance between purine and pyrimidine incorporation. Our results shed light on the mechanisms controlling 8-oxo-dGMP incorporation in Pol λ and on the importance of interactions with the incoming dNTP to determine selectivity in family X DNA polymerases.

PubMed: 26220180
DOI: 10.1093/nar/gkv760

実験手法

X-RAY DIFFRACTION (2.4 Å)