5DDM

Human DNA polymerase lambda- Apoenzyme and complex with 6 paired DNA

5DDM の概要

• エントリーDOI: 10.2210/pdb5ddm/pdb
• 関連するPDBエントリー: 5DDY
• 分子名称: DNA polymerase lambda, DNA (5'-D(*CP*AP*GP*TP*AP*C)-3'), DNA (5'-D(P*GP*TP*AP*CP*TP*G)-3'), ... (6 entities in total)
• 機能のキーワード: dna polymerase lambda, 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: 78696.00

構造登録者

Liu, M.S.,Tsai, M.D. (登録日: 2015-08-25, 公開日: 2016-02-24, 最終更新日: 2024-11-20)

主引用文献

Liu, M.S.,Tsai, H.Y.,Liu, X.X.,Ho, M.C.,Wu, W.J.,Tsai, M.D.
Structural Mechanism for the Fidelity Modulation of DNA Polymerase lambda
J.Am.Chem.Soc., 138:2389-2398, 2016

PubMed Abstract: The mechanism of DNA polymerase (pol) fidelity is of fundamental importance in chemistry and biology. While high-fidelity pols have been well studied, much less is known about how some pols achieve medium or low fidelity with functional importance. Here we examine how human DNA polymerase λ (Pol λ) achieves medium fidelity by determining 12 crystal structures and performing pre-steady-state kinetic analyses. We showed that apo-Pol λ exists in the closed conformation, unprecedentedly with a preformed MgdNTP binding pocket, and binds MgdNTP readily in the active conformation in the absence of DNA. Since prebinding of MgdNTP could lead to very low fidelity as shown previously, it is attenuated in Pol λ by a hydrophobic core including Leu431, Ile492, and the Tyr505/Phe506 motif. We then predicted and demonstrated that L431A mutation enhances MgdNTP prebinding and lowers the fidelity. We also hypothesized that the MgdNTP-prebinding ability could stabilize a mismatched ternary complex and destabilize a matched ternary complex, and provided evidence with structures in both forms. Our results demonstrate that, while high-fidelity pols follow a common paradigm, Pol λ has developed specific conformations and mechanisms for its medium fidelity. Structural comparison with other pols also suggests that different pols likely utilize different conformational changes and microscopic mechanisms to achieve their catalytic functions with varying fidelities.

PubMed: 26836966
DOI: 10.1021/jacs.5b13368

実験手法

X-RAY DIFFRACTION (2.802 Å)