+
検索条件

キーワード
著者・登録者
ジャーナル
IF	>30 >20 >10 >5 all

-
Structure paper

タイトル	Coupling of ssRNA cleavage with DNase activity in type III-A CRISPR-Csm revealed by cryo-EM and biochemistry.
ジャーナル・号・ページ	Cell Res, Vol. 29, Issue 4, Page 305-312, Year 2019
掲載日	2019年2月27日
著者	Minghui Guo / Kaiming Zhang / Yuwei Zhu / Grigore D Pintilie / Xiaoyu Guan / Shanshan Li / Michael F Schmid / Zhuo Ma / Wah Chiu / Zhiwei Huang /
PubMed 要旨	The type III CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated genes) systems are bacterially encoded adaptive immune systems for defense against invading ...The type III CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated genes) systems are bacterially encoded adaptive immune systems for defense against invading nucleic acids. They accomplish this task through the coordinated cleavage of invading substrates of single-stranded RNA and DNA (ssDNA and ssRNA) by the Csm (type III-A) or Cmr (type III-B) effector complexes. The ssRNA is complementarily bound to the CRISPR RNA (crRNA). However, the structural basis for the DNase and RNase activation of the Csm nucleoprotein complex is largely unknown. Here we report cryo-EM structures of the Csm-crRNA complex, with or without target ssRNA, at near-atomic resolution. Our cryo-EM maps allow us to build atomic models of the key macromolecular components, including Cas10, Csm2, Csm3, Csm4, crRNA and the invading ssRNA. Our structure resolves unambiguously the stoichiometry and tertiary structures of the Csm protein complex and the interactions between protein components and the crRNA/ssRNA. Interestingly, the new atomic structures of the Csm proteins presented here are similar to those of previously known Csm proteins in other species despite their low sequence similarity. Our combined structural and biochemical data suggest that ssRNA cleavage is preferentially carried out near its 5'-end, that the extent of interactions among the ssRNA, crRNA and the protein components regulates the DNase activity of the Csm complex, and that the 3' flanking sequence of ssRNA activates the Cas10 DNase activity allosterically.
リンク	Cell Res / PubMed:30814678 / PubMed Central
手法	EM (単粒子)
解像度	3.3 - 3.5 Å
構造データ	0516 6nud EMDB-0516, PDB-6nud: Small conformation of ssRNA-bound CRISPR_Csm complex 手法: EM (単粒子) / 解像度: 3.5 Å EMDB-0517: Big conformation of ssRNA-bound CRISPR_Csm complex 手法: EM (単粒子) / 解像度: 3.4 Å EMDB-0518: Big conformation of apo CRISPR_Csm complex 手法: EM (単粒子) / 解像度: 3.4 Å 0519 6nue EMDB-0519, PDB-6nue: Small conformation of apo CRISPR_Csm complex 手法: EM (単粒子) / 解像度: 3.3 Å
化合物	ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP / ATP, エネルギー貯蔵分子*YM / アデノシン三リン酸
由来	streptococcus thermophilus (ストレプトコッカス・サリバリウス亜種サーモフィラス)
キーワード	HYDROLASE (加水分解酵素) / TRANSFERASE/RNA / CRISPR (CRISPR) / Type III-A / ssRNAase / ssDNase / TRANSFERASE-RNA complex