6NJT

Mouse endonuclease G mutant - H97A

6NJT の概要

• エントリーDOI: 10.2210/pdb6njt/pdb
• 分子名称: Endonuclease G, mitochondrial, MAGNESIUM ION, CHLORIDE ION, ... (5 entities in total)
• 機能のキーワード: endonuclease, recombination
• 由来する生物種: Mus musculus (Mouse)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 56702.17

構造登録者

Vander Zanden, C.M.,Ho, E.N.,Czarny, R.S.,Robertson, A.B.,Ho, P.S. (登録日: 2019-01-04, 公開日: 2020-01-08, 最終更新日: 2024-10-30)

主引用文献

Vander Zanden, C.M.,Czarny, R.S.,Ho, E.N.,Robertson, A.B.,Ho, P.S.
Structural adaptation of vertebrate endonuclease G for 5-hydroxymethylcytosine recognition and function.
Nucleic Acids Res., 48:3962-3974, 2020

PubMed Abstract: Modified DNA bases functionally distinguish the taxonomic forms of life-5-methylcytosine separates prokaryotes from eukaryotes and 5-hydroxymethylcytosine (5hmC) invertebrates from vertebrates. We demonstrate here that mouse endonuclease G (mEndoG) shows specificity for both 5hmC and Holliday junctions. The enzyme has higher affinity (>50-fold) for junctions over duplex DNAs. A 5hmC-modification shifts the position of the cut site and increases the rate of DNA cleavage in modified versus unmodified junctions. The crystal structure of mEndoG shows that a cysteine (Cys69) is positioned to recognize 5hmC through a thiol-hydroxyl hydrogen bond. Although this Cys is conserved from worms to mammals, a two amino acid deletion in the vertebrate relative to the invertebrate sequence unwinds an α-helix, placing the thiol of Cys69 into the mEndoG active site. Mutations of Cys69 with alanine or serine show 5hmC-specificity that mirrors the hydrogen bonding potential of the side chain (C-H < S-H < O-H). A second orthogonal DNA binding site identified in the mEndoG structure accommodates a second arm of a junction. Thus, the specificity of mEndoG for 5hmC and junctions derives from structural adaptations that distinguish the vertebrate from the invertebrate enzyme, thereby thereby supporting a role for 5hmC in recombination processes.

PubMed: 32095813
DOI: 10.1093/nar/gkaa117

実験手法

X-RAY DIFFRACTION (2.07 Å)