4QH9

Crystal structure of Mn2+ bound human APE1

4QH9 の概要

• エントリーDOI: 10.2210/pdb4qh9/pdb
• 関連するPDBエントリー: 4QHD 4QHE
• 分子名称: DNA-(apurinic or apyrimidinic site) lyase, 1,2-ETHANEDIOL, MANGANESE (II) ION, ... (4 entities in total)
• 機能のキーワード: beta sandwich, endonuclease, dna-binding, nucleus, lyase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Nucleus. DNA-(apurinic or apyrimidinic site) lyase, mitochondrial: Mitochondrion: P27695
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 32500.79

構造登録者

Chen, Q.,He, H.,Georgiadis, M.M. (登録日: 2014-05-27, 公開日: 2014-11-12, 最終更新日: 2024-02-28)

主引用文献

He, H.,Chen, Q.,Georgiadis, M.M.
High-resolution crystal structures reveal plasticity in the metal binding site of apurinic/apyrimidinic endonuclease I.
Biochemistry, 53:6520-6529, 2014

PubMed Abstract: Apurinic/apyrimidinic endonuclease I (APE1) is an essential base excision repair enzyme that catalyzes a Mg²⁺-dependent reaction in which the phosphodiester backbone is cleaved 5' of an abasic site in duplex DNA. This reaction has been proposed to involve either one or two metal ions bound to the active site. In the present study, we report crystal structures of Mg²⁺, Mn²⁺, and apo-APE1 determined at 1.4, 2.2, and 1.65 Å, respectively, representing two of the highest resolution structures yet reported for APE1. In our structures, a single well-ordered Mn²⁺ ion was observed coordinated by D70 and E96; the Mg²⁺ site exhibited disorder modeled as two closely positioned sites coordinated by D70 and E96 or E96 alone. Direct metal binding analysis of wild-type, D70A, and E96A APE1, as assessed by differential scanning fluorimetry, indicated a role for D70 and E96 in binding of Mg²⁺ or Mn²⁺ to APE1. Consistent with the disorder exhibited by Mg²⁺ bound to the active site, two different conformations of E96 were observed coordinated to Mg²⁺. A third conformation for E96 in the apo structure is similar to that observed in the APE1-DNA-Mg²⁺ complex structure. Thus, binding of Mg²⁺ in three different positions within the active site of APE1 in these crystal structures corresponds directly with three different conformations of E96. Taken together, our results are consistent with the initial capture of metal by D70 and E96 and repositioning of Mg²⁺ facilitated by the structural plasticity of E96 in the active site.

PubMed: 25251148
DOI: 10.1021/bi500676p

実験手法

X-RAY DIFFRACTION (2.175 Å)