EMDB/PDB/SASBDBから引用されている文献のデータベース

キーワード
構造解析手法	All X線回折 NMR 電子顕微鏡小角散乱中性子線回折線維回折粉末回折赤外分光 EPR FRET 理論モデルハイブリッド
著者・登録者
ジャーナル
IF	>30 >20 >10 >5 all

タイトル	The proofreading mechanism of the human leading-strand DNA polymerase ε holoenzyme.
ジャーナル・号・ページ	Proc Natl Acad Sci U S A, Vol. 122, Issue 22, Page e2507232122, Year 2025
掲載日	2025年6月3日
著者	Feng Wang / Qing He / Michael E O'Donnell / Huilin Li /
PubMed 要旨	The eukaryotic leading-strand DNA polymerase ε (Polε) is a dual-function enzyme with a proofreading 3'-5' exonuclease () site located 40 Å from the DNA synthesizing site. Errors in Polε ...The eukaryotic leading-strand DNA polymerase ε (Polε) is a dual-function enzyme with a proofreading 3'-5' exonuclease () site located 40 Å from the DNA synthesizing site. Errors in Polε proofreading can cause various mutations, including C-to-G transversions, the most prevalent mutation in cancers and genetic diseases. Polε interacts with all three subunits of the PCNA ring to assemble a functional holoenzyme. Despite previous studies on proofreading of several Pol's, how Polε-or any Pol complexed with its sliding clamp-proofreads a mismatch generated in situ has been unknown. We show here by cryo-EM that a template/primer DNA substrate with a preexisting mismatch cannot enter the site of Polε-PCNA holoenzyme, but a mismatch generated in situ in the site yields three bona fide proofreading intermediates of Polε-PCNA holoenzyme. These intermediates reveal how the mismatch is dislodged from the site, how the DNA unwinds six base pairs, and how the unpaired primer 3'-end is inserted into the site for cleavage. These results unexpectedly demonstrate that PCNA imposes strong steric constraints that extend unwinding and direct the trajectory of mismatched DNA and that this trajectory is dramatically different than for Polε in the absence of PCNA. These findings suggest a physiologically relevant proofreading mechanism for the human Polε holoenzyme.
リンク	Proc Natl Acad Sci U S A / PubMed:40440070 / PubMed Central
手法	EM (単粒子)
解像度	3.11 - 3.88 Å
構造データ	49299 9ne6 EMDB-49299, PDB-9ne6: Human polymerase epsilon bound to PCNA and DNA with an in-situ-generated mismatch in the mismatch-editing state 手法: EM (単粒子) / 解像度: 3.11 Å 49300 9ne7 EMDB-49300, PDB-9ne7: Human polymerase epsilon bound to PCNA and DNA with an in-situ-generated mismatch in the Pol-backtracking state 手法: EM (単粒子) / 解像度: 3.53 Å 49301 9ne8 EMDB-49301, PDB-9ne8: Human polymerase epsilon bound to PCNA and DNA with an in-situ-generated mismatch in the mismatch-locking state 手法: EM (単粒子) / 解像度: 3.6 Å 49302 9ne9 EMDB-49302, PDB-9ne9: Human polymerase epsilon bound to PCNA and DNA with a pre-existing mismatch in the blocked conformation I 手法: EM (単粒子) / 解像度: 3.88 Å 49303 9nea EMDB-49303, PDB-9nea: Human polymerase epsilon bound to PCNA and DNA with a pre-existing mismatch in the blocked conformation II 手法: EM (単粒子) / 解像度: 3.81 Å
化合物	ChemComp-SF4: IRON/SULFUR CLUSTER ChemComp-MG: Unknown entry / マグネシウムジカチオン
由来	homo sapiens (ヒト) synthetic construct (人工物)
キーワード	REPLICATION / DNA polymerase / exo / holoenzyme / DNA