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データを開く
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基本情報
| 登録情報 | データベース: PDB / ID: 9ask | |||||||||||||||||||||||||||||||||||||||
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| タイトル | Human DNA polymerase theta helicase domain dimer, apo-form | |||||||||||||||||||||||||||||||||||||||
要素 | DNA polymerase theta | |||||||||||||||||||||||||||||||||||||||
キーワード | TRANSFERASE / DNA BINDING PROTEIN / DNA repair / helicase / ATPase | |||||||||||||||||||||||||||||||||||||||
| 機能・相同性 | 機能・相同性情報double-strand break repair via alternative nonhomologous end joining / HDR through MMEJ (alt-NHEJ) / single-stranded DNA helicase activity / replication fork processing / mitochondrial nucleoid / site of DNA damage / 5'-deoxyribose-5-phosphate lyase activity / error-prone translesion synthesis / negative regulation of double-strand break repair via homologous recombination / somatic hypermutation of immunoglobulin genes ...double-strand break repair via alternative nonhomologous end joining / HDR through MMEJ (alt-NHEJ) / single-stranded DNA helicase activity / replication fork processing / mitochondrial nucleoid / site of DNA damage / 5'-deoxyribose-5-phosphate lyase activity / error-prone translesion synthesis / negative regulation of double-strand break repair via homologous recombination / somatic hypermutation of immunoglobulin genes / DNA helicase activity / protein homooligomerization / base-excision repair / RNA-directed DNA polymerase / RNA-directed DNA polymerase activity / double-strand break repair / site of double-strand break / DNA-directed DNA polymerase / DNA helicase / damaged DNA binding / DNA-directed DNA polymerase activity / DNA repair / DNA damage response / chromatin binding / magnesium ion binding / Golgi apparatus / ATP hydrolysis activity / nucleoplasm / ATP binding / identical protein binding / nucleus / cytosol 類似検索 - 分子機能 | |||||||||||||||||||||||||||||||||||||||
| 生物種 | Homo sapiens (ヒト) | |||||||||||||||||||||||||||||||||||||||
| 手法 | 電子顕微鏡法 / 単粒子再構成法 / クライオ電子顕微鏡法 / 解像度: 3.6 Å | |||||||||||||||||||||||||||||||||||||||
データ登録者 | Ito, F. / Li, Z. / Chen, X.S. | |||||||||||||||||||||||||||||||||||||||
| 資金援助 | 米国, 1件
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引用 | ジャーナル: Nat Commun / 年: 2025タイトル: Structural basis for Polθ-helicase DNA binding and microhomology-mediated end-joining. 著者: Fumiaki Ito / Ziyuan Li / Leonid Minakhin / Htet A Khant / Richard T Pomerantz / Xiaojiang S Chen / ![]() 要旨: DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous ...DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous recombination (HR) and non-homologous end joining (NHEJ). In HR-deficient cells, DNA polymerase theta (Polθ) becomes critical for DSB repair via microhomology-mediated end joining (MMEJ), also termed theta-mediated end joining (TMEJ). Thus, Polθ is synthetically lethal with BRCA1/2 and other HR factors, underscoring its potential as a therapeutic target in HR-deficient cancers. However, the molecular mechanisms governing Polθ-mediated MMEJ remain poorly understood. Here we present a series of cryo-electron microscopy structures of the Polθ helicase domain (Polθ-hel) in complex with DNA containing different 3'-ssDNA overhangs. The structures reveal the sequential conformations adopted by Polθ-hel during the critical phases of DNA binding, microhomology searching, and microhomology annealing. The stepwise conformational changes within the Polθ-hel subdomains and its functional dimeric state are pivotal for aligning the 3'-ssDNA overhangs, facilitating the microhomology search and subsequent annealing necessary for DSB repair via MMEJ. Our findings illustrate the essential molecular switches within Polθ-hel that orchestrate the MMEJ process in DSB repair, laying the groundwork for the development of targeted therapies against the Polθ-hel. #1: ジャーナル: bioRxiv / 年: 2024 タイトル: Structural Basis for Polθ-Helicase DNA Binding and Microhomology-Mediated End-Joining. 著者: Fumiaki Ito / Ziyuan Li / Leonid Minakhin / Htet A Khant / Richard T Pomerantz / Xiaojiang S Chen / ![]() 要旨: DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous ...DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous recombination (HR) and non-homologous end joining (NHEJ). In HR-deficient cells, DNA polymerase theta (Polθ) becomes critical for DSB repair via microhomology-mediated end joining (MMEJ), also termed theta-mediated end joining (TMEJ). Thus, Polθ is synthetically lethal with BRCA1/2 and other HR factors, underscoring its potential as a therapeutic target in HR-deficient cancers. However, the molecular mechanisms governing Polθ-mediated MMEJ remain poorly understood. Here we present a series of cryo-electron microscopy structures of the Polθ helicase domain (Polθ-hel) in complex with DNA containing 3'-overhang. The structures reveal the sequential conformations adopted by Polθ-hel during the critical phases of DNA binding, microhomology searching, and microhomology annealing. The stepwise conformational changes within the Polθ-hel subdomains and its functional dimeric state are pivotal for aligning the 3'-overhangs, facilitating the microhomology search and subsequent annealing necessary for DSB repair via MMEJ. Our findings illustrate the essential molecular switches within Polθ-hel that orchestrate the MMEJ process in DSB repair, laying the groundwork for the development of targeted therapies against the Polθ-hel. | |||||||||||||||||||||||||||||||||||||||
| 履歴 |
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構造の表示
| 構造ビューア | 分子: Molmil Jmol/JSmol |
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ダウンロードとリンク
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ダウンロード
| PDBx/mmCIF形式 | 9ask.cif.gz | 262.7 KB | 表示 | PDBx/mmCIF形式 |
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| PDB形式 | pdb9ask.ent.gz | 209 KB | 表示 | PDB形式 |
| PDBx/mmJSON形式 | 9ask.json.gz | ツリー表示 | PDBx/mmJSON形式 | |
| その他 | その他のダウンロード |
-検証レポート
| アーカイブディレクトリ | https://data.pdbj.org/pub/pdb/validation_reports/as/9ask ftp://data.pdbj.org/pub/pdb/validation_reports/as/9ask | HTTPS FTP |
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-関連構造データ
| 関連構造データ | ![]() 43817MC ![]() 8w0aC ![]() 9asjC ![]() 9aslC ![]() 9c5qC ![]() 40760 ![]() 40761 M: このデータのモデリングに利用したマップデータ C: 同じ文献を引用 ( |
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| 類似構造データ | 類似検索 - 機能・相同性 F&H 検索 |
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リンク
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集合体
| 登録構造単位 | ![]()
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要素
| #1: タンパク質 | 分子量: 99802.539 Da / 分子数: 2 / 由来タイプ: 組換発現 / 由来: (組換発現) Homo sapiens (ヒト) / 遺伝子: POLQ, POLH / 発現宿主: ![]() Has protein modification | N | |
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-実験情報
-実験
| 実験 | 手法: 電子顕微鏡法 |
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| EM実験 | 試料の集合状態: PARTICLE / 3次元再構成法: 単粒子再構成法 |
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試料調製
| 構成要素 | 名称: Human DNA polymerase theta helicase domain dimer, apo-form タイプ: COMPLEX / Entity ID: all / 由来: RECOMBINANT |
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| 分子量 | 値: 0.199 MDa / 実験値: NO |
| 由来(天然) | 生物種: Homo sapiens (ヒト) |
| 由来(組換発現) | 生物種: ![]() |
| 緩衝液 | pH: 7.5 |
| 試料 | 濃度: 1 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES |
| 急速凍結 | 装置: FEI VITROBOT MARK IV / 凍結剤: ETHANE / 湿度: 100 % / 凍結前の試料温度: 277 K |
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電子顕微鏡撮影
| 顕微鏡 | モデル: TFS GLACIOS |
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| 電子銃 | 電子線源: FIELD EMISSION GUN / 加速電圧: 200 kV / 照射モード: FLOOD BEAM |
| 電子レンズ | モード: BRIGHT FIELD / 倍率(公称値): 150000 X / 最大 デフォーカス(公称値): 3000 nm / 最小 デフォーカス(公称値): 1000 nm / Cs: 2 mm / C2レンズ絞り径: 50 µm |
| 撮影 | 平均露光時間: 8 sec. / 電子線照射量: 58 e/Å2 フィルム・検出器のモデル: FEI FALCON IV (4k x 4k) 撮影したグリッド数: 1 / 実像数: 4511 |
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解析
| EMソフトウェア |
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| CTF補正 | タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
| 粒子像の選択 | 選択した粒子像数: 3961362 | ||||||||||||||||||||||||
| 3次元再構成 | 解像度: 3.6 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 280269 / クラス平均像の数: 1 / 対称性のタイプ: POINT | ||||||||||||||||||||||||
| 拘束条件 |
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万見について




Homo sapiens (ヒト)
米国, 1件
引用










PDBj




FIELD EMISSION GUN