+
データを開く
-
基本情報
登録情報 | データベース: PDB / ID: 9ask | |||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
タイトル | Human DNA polymerase theta helicase domain dimer, apo-form | |||||||||||||||||||||||||||||||||||||||
![]() | DNA polymerase theta | |||||||||||||||||||||||||||||||||||||||
![]() | TRANSFERASE / DNA BINDING PROTEIN / DNA repair / helicase / ATPase | |||||||||||||||||||||||||||||||||||||||
機能・相同性 | ![]() double-strand break repair via alternative nonhomologous end joining / HDR through MMEJ (alt-NHEJ) / single-stranded DNA helicase activity / replication fork processing / site of DNA damage / mitochondrial nucleoid / 5'-deoxyribose-5-phosphate lyase activity / somatic hypermutation of immunoglobulin genes / error-prone translesion synthesis / negative regulation of double-strand break repair via homologous recombination ...double-strand break repair via alternative nonhomologous end joining / HDR through MMEJ (alt-NHEJ) / single-stranded DNA helicase activity / replication fork processing / site of DNA damage / mitochondrial nucleoid / 5'-deoxyribose-5-phosphate lyase activity / somatic hypermutation of immunoglobulin genes / error-prone translesion synthesis / negative regulation of double-strand break repair via homologous recombination / RNA-directed DNA polymerase activity / DNA helicase activity / base-excision repair / protein homooligomerization / RNA-directed DNA polymerase / double-strand break repair / site of double-strand break / DNA helicase / damaged DNA binding / DNA-directed DNA polymerase / 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 | ![]() | |||||||||||||||||||||||||||||||||||||||
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 | |||||||||||||||||||||||||||||||||||||||
![]() | Ito, F. / Li, Z. / Chen, X.S. | |||||||||||||||||||||||||||||||||||||||
資金援助 | ![]()
| |||||||||||||||||||||||||||||||||||||||
![]() | ![]() 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 |
|
-
構造の表示
構造ビューア | 分子: ![]() ![]() |
---|
-
ダウンロードとリンク
-
ダウンロード
PDBx/mmCIF形式 | ![]() | 262.7 KB | 表示 | ![]() |
---|---|---|---|---|
PDB形式 | ![]() | 209 KB | 表示 | ![]() |
PDBx/mmJSON形式 | ![]() | ツリー表示 | ![]() | |
その他 | ![]() |
-検証レポート
アーカイブディレクトリ | ![]() ![]() | HTTPS FTP |
---|
-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 ( |
---|---|
類似構造データ | 類似検索 - 機能・相同性 ![]() |
-
リンク
-
集合体
登録構造単位 | ![]()
|
---|---|
1 |
|
-
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) ![]() ![]() ![]() Has protein modification | N | |
---|
-実験情報
-実験
実験 | 手法: 電子顕微鏡法 |
---|---|
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 |
-
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 |
---|---|
分子量 | 値: 0.199 MDa / 実験値: NO |
由来(天然) | 生物種: ![]() |
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 |
-
電子顕微鏡撮影
顕微鏡 | モデル: TFS GLACIOS |
---|---|
電子銃 | 電子線源: ![]() |
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 |
-
解析
EMソフトウェア |
| ||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 |
|