1AKO

EXONUCLEASE III FROM ESCHERICHIA COLI

1AKO の概要

• エントリーDOI: 10.2210/pdb1ako/pdb
• 分子名称: EXONUCLEASE III (2 entities in total)
• 機能のキーワード: nuclease, exonuclease, ap-endonuclease, dna repair
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 31011.17

構造登録者

Mol, C.D.,Kuo, C.-F.,Thayer, M.M.,Cunningham, R.P.,Tainer, J.A. (登録日: 1997-05-26, 公開日: 1997-08-20, 最終更新日: 2024-02-07)

主引用文献

Mol, C.D.,Kuo, C.F.,Thayer, M.M.,Cunningham, R.P.,Tainer, J.A.
Structure and function of the multifunctional DNA-repair enzyme exonuclease III.
Nature, 374:381-386, 1995

PubMed Abstract: The repair of DNA requires the removal of abasic sites, which are constantly generated in vivo both spontaneously and by enzymatic removal of uracil, and of bases damaged by active oxygen species, alkylating agents and ionizing radiation. The major apurinic/apyrimidinic (AP) DNA-repair endonuclease in Escherichia coli is the multifunctional enzyme exonuclease III, which also exhibits 3'-repair diesterase, 3'-->5' exonuclease, 3'-phosphomonoesterase and ribonuclease activities. We report here the 1.7 A resolution crystal structure of exonuclease III which reveals a 2-fold symmetric, four-layered alpha beta fold with similarities to both deoxyribonuclease I and RNase H. In the ternary complex determined at 2.6 A resolution, Mn2+ and dCMP bind to exonuclease III at one end of the alpha beta-sandwich, in a region dominated by positive electrostatic potential. Residues conserved among AP endonucleases from bacteria to man cluster within this active site and appear to participate in phosphate-bond cleavage at AP sites through a nucleophilic attack facilitated by a single bound metal ion.

PubMed: 7885481
DOI: 10.1038/374381a0

実験手法

X-RAY DIFFRACTION (1.7 Å)