6IG1

DNA polymerase IV - DNA ternary complex 10

「5YV4」から置き換えられました

6IG1 の概要

• エントリーDOI: 10.2210/pdb6ig1/pdb
• 分子名称: DNA polymerase IV, DTN3, MAGNESIUM ION, ... (6 entities in total)
• 機能のキーワード: dna polymerase, dna binding protein, dna binding protein-dna complex
• 由来する生物種: Escherichia coli K-12; 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 103776.22

構造登録者

Kottur, J.,Nair, D.T. (登録日: 2018-09-21, 公開日: 2018-11-28, 最終更新日: 2023-11-22)

主引用文献

Kottur, J.,Nair, D.T.
Pyrophosphate hydrolysis is an intrinsic and critical step of the DNA synthesis reaction.
Nucleic Acids Res., 46:5875-5885, 2018

PubMed Abstract: DNA synthesis by DNA polymerases (dPols) is central to duplication and maintenance of the genome in all living organisms. dPols catalyze the formation of a phosphodiester bond between the incoming deoxynucleoside triphosphate and the terminal primer nucleotide with the release of a pyrophosphate (PPi) group. It is believed that formation of the phosphodiester bond is an endergonic reaction and PPi has to be hydrolyzed by accompanying pyrophosphatase enzymes to ensure that the free energy change of the DNA synthesis reaction is negative and it can proceed in the forward direction. The fact that DNA synthesis proceeds in vitro in the absence of pyrophosphatases represents a long-standing conundrum regarding the thermodynamics of the DNA synthesis reaction. Using time-resolved crystallography, we show that hydrolysis of PPi is an intrinsic and critical step of the DNA synthesis reaction catalyzed by dPols. The hydrolysis of PPi occurs after the formation of the phosphodiester bond and ensures that the DNA synthesis reaction is energetically favorable without the need for additional enzymes. Also, we observe that DNA synthesis is a two Mg2+ ion assisted stepwise associative SN2 reaction. Overall, this study provides deep temporal insight regarding the primary enzymatic reaction responsible for genome duplication.

PubMed: 29850882
DOI: 10.1093/nar/gky402

実験手法

X-RAY DIFFRACTION (1.97 Å)