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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: 9zq6 | |||||||||||||||||||||||||||
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| タイトル | Structure of SpyCas9 in complex with the anti-CRISPR protein AcrIIA26 | |||||||||||||||||||||||||||
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キーワード | IMMUNE SYSTEM / CRISPR / Cas9 / Acr | |||||||||||||||||||||||||||
| 機能・相同性 | 機能・相同性情報maintenance of CRISPR repeat elements / 3'-5' exonuclease activity / DNA endonuclease activity / defense response to virus / 加水分解酵素; エステル加水分解酵素 / DNA binding / RNA binding / metal ion binding 類似検索 - 分子機能 | |||||||||||||||||||||||||||
| 生物種 | Streptococcus pyogenes M1 GAS (化膿レンサ球菌) Streptococcus (バクテリア) | |||||||||||||||||||||||||||
| 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: 2.98 Å | |||||||||||||||||||||||||||
データ登録者 | Zheng, I. / Learn, B. / Bailey, S. | |||||||||||||||||||||||||||
| 資金援助 | 米国, 1件
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引用 | ジャーナル: Biochem J / 年: 2026タイトル: Structural basis for inhibition of SpyCas9 by the anti-CRISPR protein AcrIIA26. 著者: Iris Zheng / Brian Learn / Scott Bailey / ![]() 要旨: CRISPR-Cas9 systems provide adaptive immunity in prokaryotes by targeting and cleaving invading phage DNA. In response, phages have evolved anti-CRISPR (Acr) proteins to inhibit Cas9 and evade this ...CRISPR-Cas9 systems provide adaptive immunity in prokaryotes by targeting and cleaving invading phage DNA. In response, phages have evolved anti-CRISPR (Acr) proteins to inhibit Cas9 and evade this immune response. AcrIIA26 is a type II-A anti-CRISPR protein that inhibits Streptococcus pyogenes Cas9 (SpyCas9) DNA binding, but its molecular mechanism remains unclear. Here, we determined the 3.0 Å resolution cryo-EM structure of AcrIIA26 in complex with SpyCas9-single-guide RNA, revealing a dual inhibition mechanism. AcrIIA26 adopts a novel fold comprising a central β-sheet flanked by two α-helical bundles. The 5-helix bundle, which features a negatively charged surface whose shape mimics duplex DNA, occupies the same position as the protospacer adjacent motif (PAM) duplex in target-bound Cas9. This directly blocks PAM recognition by burying critical residues R1333 and R1335 in the PAM-interacting domain. Mutagenesis confirmed that residues E49 and D50 in AcrIIA26 are essential for this interaction. Simultaneously, the 4-helix bundle binds the Cas9 REC lobe and sterically prevents the conformational changes required for Cas9 activation, with mutation of AcrIIA26 F121 completely eliminating inhibitory activity. Structural comparisons reveal that despite diverse folds, multiple anti-CRISPRs convergently evolved to block PAM recognition, highlighting this as a critical vulnerability in Cas9 function. Our findings provide mechanistic insights into AcrIIA26 inhibition and offer a foundation for engineering improved Cas9 off-switches for genome editing applications. #1: ジャーナル: Commun Biol / 年: 2019 タイトル: SPHIRE-crYOLO is a fast and accurate fully automated particle picker for cryo-EM. 著者: Thorsten Wagner / Felipe Merino / Markus Stabrin / Toshio Moriya / Claudia Antoni / Amir Apelbaum / Philine Hagel / Oleg Sitsel / Tobias Raisch / Daniel Prumbaum / Dennis Quentin / Daniel ...著者: Thorsten Wagner / Felipe Merino / Markus Stabrin / Toshio Moriya / Claudia Antoni / Amir Apelbaum / Philine Hagel / Oleg Sitsel / Tobias Raisch / Daniel Prumbaum / Dennis Quentin / Daniel Roderer / Sebastian Tacke / Birte Siebolds / Evelyn Schubert / Tanvir R Shaikh / Pascal Lill / Christos Gatsogiannis / Stefan Raunser / ![]() 要旨: Selecting particles from digital micrographs is an essential step in single-particle electron cryomicroscopy (cryo-EM). As manual selection of complete datasets-typically comprising thousands of ...Selecting particles from digital micrographs is an essential step in single-particle electron cryomicroscopy (cryo-EM). As manual selection of complete datasets-typically comprising thousands of particles-is a tedious and time-consuming process, numerous automatic particle pickers have been developed. However, non-ideal datasets pose a challenge to particle picking. Here we present the particle picking software crYOLO which is based on the deep-learning object detection system You Only Look Once (YOLO). After training the network with 200-2500 particles per dataset it automatically recognizes particles with high recall and precision while reaching a speed of up to five micrographs per second. Further, we present a general crYOLO network able to pick from previously unseen datasets, allowing for completely automated on-the-fly cryo-EM data preprocessing during data acquisition. crYOLO is available as a standalone program under http://sphire.mpg.de/ and is distributed as part of the image processing workflow in SPHIRE. #2: ジャーナル: Nat Methods / 年: 2020 タイトル: Non-uniform refinement: adaptive regularization improves single-particle cryo-EM reconstruction. 著者: Ali Punjani / Haowei Zhang / David J Fleet / ![]() 要旨: Cryogenic electron microscopy (cryo-EM) is widely used to study biological macromolecules that comprise regions with disorder, flexibility or partial occupancy. For example, membrane proteins are ...Cryogenic electron microscopy (cryo-EM) is widely used to study biological macromolecules that comprise regions with disorder, flexibility or partial occupancy. For example, membrane proteins are often kept in solution with detergent micelles and lipid nanodiscs that are locally disordered. Such spatial variability negatively impacts computational three-dimensional (3D) reconstruction with existing iterative refinement algorithms that assume rigidity. We introduce non-uniform refinement, an algorithm based on cross-validation optimization, which automatically regularizes 3D density maps during refinement to account for spatial variability. Unlike common shift-invariant regularizers, non-uniform refinement systematically removes noise from disordered regions, while retaining signal useful for aligning particle images, yielding dramatically improved resolution and 3D map quality in many cases. We obtain high-resolution reconstructions for multiple membrane proteins as small as 100 kDa, demonstrating increased effectiveness of cryo-EM for this class of targets critical in structural biology and drug discovery. Non-uniform refinement is implemented in the cryoSPARC software package. | |||||||||||||||||||||||||||
| 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 | 9zq6.cif.gz | 438.4 KB | 表示 | PDBx/mmCIF形式 |
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| PDB形式 | pdb9zq6.ent.gz | 279.3 KB | 表示 | PDB形式 |
| PDBx/mmJSON形式 | 9zq6.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/zq/9zq6 ftp://data.pdbj.org/pub/pdb/validation_reports/zq/9zq6 | HTTPS FTP |
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-関連構造データ
| 関連構造データ | ![]() 74542MC 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: 158699.844 Da / 分子数: 1 / 由来タイプ: 組換発現 由来: (組換発現) Streptococcus pyogenes M1 GAS (化膿レンサ球菌)遺伝子: cas9, csn1, SPy_1046 / 発現宿主: ![]() 参照: UniProt: Q99ZW2, 加水分解酵素; エステル加水分解酵素 |
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| #2: タンパク質 | 分子量: 21449.260 Da / 分子数: 1 / 由来タイプ: 組換発現 / 由来: (組換発現) Streptococcus (バクテリア) / 発現宿主: ![]() |
| #3: RNA鎖 | 分子量: 38697.953 Da / 分子数: 1 / 由来タイプ: 合成 由来: (合成) Streptococcus pyogenes M1 GAS (化膿レンサ球菌) |
| Has protein modification | N |
-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: Cas9-sgRNA-AcrIIA26 complex / タイプ: COMPLEX / Entity ID: all / 由来: RECOMBINANT |
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| 由来(天然) | 生物種: Streptococcus pyogenes M1 GAS (化膿レンサ球菌) |
| 由来(組換発現) | 生物種: ![]() |
| 緩衝液 | pH: 7.5 |
| 試料 | 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES |
| 急速凍結 | 凍結剤: ETHANE |
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電子顕微鏡撮影
| 実験機器 | ![]() モデル: Titan Krios / 画像提供: FEI Company |
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| 顕微鏡 | モデル: TFS KRIOS |
| 電子銃 | 電子線源: FIELD EMISSION GUN / 加速電圧: 300 kV / 照射モード: OTHER |
| 電子レンズ | モード: BRIGHT FIELD / 最大 デフォーカス(公称値): 3000 nm / 最小 デフォーカス(公称値): 500 nm |
| 撮影 | 電子線照射量: 40 e/Å2 フィルム・検出器のモデル: FEI FALCON IV (4k x 4k) |
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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 | ||||||||||||||||||||||||
| 3次元再構成 | 解像度: 2.98 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 59914 / 対称性のタイプ: POINT | ||||||||||||||||||||||||
| 精密化 | 交差検証法: NONE 立体化学のターゲット値: GeoStd + Monomer Library + CDL v1.2 | ||||||||||||||||||||||||
| 原子変位パラメータ | Biso mean: 68.61 Å2 | ||||||||||||||||||||||||
| 拘束条件 |
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ムービー
コントローラー
万見について




Streptococcus pyogenes M1 GAS (化膿レンサ球菌)
米国, 1件
引用


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FIELD EMISSION GUN