4GX8

Crystal structure of a DNA polymerase III alpha-epsilon chimera

4GX8 の概要

• エントリーDOI: 10.2210/pdb4gx8/pdb
• 関連するPDBエントリー: 1J53 1J54 2AXD 2GUI 2HNH 2HQA 2IDO 4GX9
• 分子名称: DNA polymerase III subunit epsilon,DNA polymerase III subunit alpha, CHLORIDE ION (3 entities in total)
• 機能のキーワード: dna polymerase iii, poliii epsilon, poliii alpha, dnaq, dnae, transferase
• 由来する生物種: Escherichia coli; 詳細
• 細胞内の位置: Cytoplasm: P10443
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 138654.80

構造登録者

Robinson, A.,Horan, N.,Xu, Z.-Q.,Dixon, N.E.,Oakley, A.J. (登録日: 2012-09-04, 公開日: 2013-04-03, 最終更新日: 2023-11-08)

主引用文献

Ozawa, K.,Horan, N.P.,Robinson, A.,Yagi, H.,Hill, F.R.,Jergic, S.,Xu, Z.Q.,Loscha, K.V.,Li, N.,Tehei, M.,Oakley, A.J.,Otting, G.,Huber, T.,Dixon, N.E.
Proofreading exonuclease on a tether: the complex between the E. coli DNA polymerase III subunits alpha, {varepsilon}, theta and beta reveals a highly flexible arrangement of the proofreading domain
Nucleic Acids Res., 41:5354-5367, 2013

PubMed Abstract: A complex of the three (αεθ) core subunits and the β2 sliding clamp is responsible for DNA synthesis by Pol III, the Escherichia coli chromosomal DNA replicase. The 1.7 Å crystal structure of a complex between the PHP domain of α (polymerase) and the C-terminal segment of ε (proofreading exonuclease) subunits shows that ε is attached to α at a site far from the polymerase active site. Both α and ε contain clamp-binding motifs (CBMs) that interact simultaneously with β2 in the polymerization mode of DNA replication by Pol III. Strengthening of both CBMs enables isolation of stable αεθ:β2 complexes. Nuclear magnetic resonance experiments with reconstituted αεθ:β2 demonstrate retention of high mobility of a segment of 22 residues in the linker that connects the exonuclease domain of ε with its α-binding segment. In spite of this, small-angle X-ray scattering data show that the isolated complex with strengthened CBMs has a compact, but still flexible, structure. Photo-crosslinking with p-benzoyl-L-phenylalanine incorporated at different sites in the α-PHP domain confirm the conformational variability of the tether. Structural models of the αεθ:β2 replicase complex with primer-template DNA combine all available structural data.

PubMed: 23580545
DOI: 10.1093/nar/gkt162

実験手法

X-RAY DIFFRACTION (1.7 Å)