ジャーナル: Nat Commun / 年: 2024 タイトル: Structural variation of types IV-A1- and IV-A3-mediated CRISPR interference. 著者: R Čepaitė / N Klein / A Mikšys / S Camara-Wilpert / V Ragožius / F Benz / A Skorupskaitė / H Becker / G Žvejytė / N Steube / G K A Hochberg / L Randau / R Pinilla-Redondo / L ...著者: R Čepaitė / N Klein / A Mikšys / S Camara-Wilpert / V Ragožius / F Benz / A Skorupskaitė / H Becker / G Žvejytė / N Steube / G K A Hochberg / L Randau / R Pinilla-Redondo / L Malinauskaitė / P Pausch / 要旨: CRISPR-Cas mediated DNA-interference typically relies on sequence-specific binding and nucleolytic degradation of foreign genetic material. Type IV-A CRISPR-Cas systems diverge from this general ...CRISPR-Cas mediated DNA-interference typically relies on sequence-specific binding and nucleolytic degradation of foreign genetic material. Type IV-A CRISPR-Cas systems diverge from this general mechanism, using a nuclease-independent interference pathway to suppress gene expression for gene regulation and plasmid competition. To understand how the type IV-A system associated effector complex achieves this interference, we determine cryo-EM structures of two evolutionarily distinct type IV-A complexes (types IV-A1 and IV-A3) bound to cognate DNA-targets in the presence and absence of the type IV-A signature DinG effector helicase. The structures reveal how the effector complexes recognize the protospacer adjacent motif and target-strand DNA to form an R-loop structure. Additionally, we reveal differences between types IV-A1 and IV-A3 in DNA interactions and structural motifs that allow for in trans recruitment of DinG. Our study provides a detailed view of type IV-A mediated DNA-interference and presents a structural foundation for engineering type IV-A-based genome editing tools.
全体 : Type IV-A3 CRISPR-Cas effector complex with DinG from Klebsiella ...
全体
名称: Type IV-A3 CRISPR-Cas effector complex with DinG from Klebsiella pneumoniae bound to crRNA and target DNA
要素
複合体: Type IV-A3 CRISPR-Cas effector complex with DinG from Klebsiella pneumoniae bound to crRNA and target DNA
複合体: CRISPR effector in complex with a DinG helicase and crRNA
タンパク質・ペプチド: CRISPR type AFERR-associated protein Csf2
タンパク質・ペプチド: CRISPR type AFERR-associated protein Csf3
タンパク質・ペプチド: CRISPR type AFERR-associated protein Csf1
RNA: crRNA
タンパク質・ペプチド: DEAD/DEAH box helicase
複合体: Double-stranded DNA
DNA: TS-DNA
DNA: NTS-DNA
リガンド: ZINC ION
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超分子 #1: Type IV-A3 CRISPR-Cas effector complex with DinG from Klebsiella ...
超分子
名称: Type IV-A3 CRISPR-Cas effector complex with DinG from Klebsiella pneumoniae bound to crRNA and target DNA タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1-#7 詳細: The Cas6 subunit found in the type IVA3 system from Klebsiella pneumoniae was present during expression, purification and complex assembly, but was not resolved due to high flexibility
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超分子 #2: CRISPR effector in complex with a DinG helicase and crRNA
超分子
名称: CRISPR effector in complex with a DinG helicase and crRNA タイプ: complex / ID: 2 / 親要素: 1 / 含まれる分子: #1-#4, #7
モデルのタイプ: INSILICO MODEL / In silico モデル: AlphaFold 詳細: AlphaFold model for chain M (DinG) was fitted using ChimeraX and Coot. PDB deposition 8RC2 was used for the remaining chains.
最終 再構成
アルゴリズム: BACK PROJECTION / 解像度のタイプ: BY AUTHOR / 解像度: 2.9 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 使用した粒子像数: 46284
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD
FSC曲線 (解像度の算出)
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原子モデル構築 1
初期モデル
Chain
PDB ID
chain_id: M, source_name: AlphaFold, initial_model_type: in silico model
source_name: PDB, initial_model_type: experimental model