ジャーナル: Mol Cell / 年: 2020 タイトル: Structures of the Cmr-β Complex Reveal the Regulation of the Immunity Mechanism of Type III-B CRISPR-Cas. 著者: Nicholas Sofos / Mingxia Feng / Stefano Stella / Tillmann Pape / Anders Fuglsang / Jinzhong Lin / Qihong Huang / Yingjun Li / Qunxin She / Guillermo Montoya / 要旨: Cmr-β is a type III-B CRISPR-Cas complex that, upon target RNA recognition, unleashes a multifaceted immune response against invading genetic elements, including single-stranded DNA (ssDNA) ...Cmr-β is a type III-B CRISPR-Cas complex that, upon target RNA recognition, unleashes a multifaceted immune response against invading genetic elements, including single-stranded DNA (ssDNA) cleavage, cyclic oligoadenylate synthesis, and also a unique UA-specific single-stranded RNA (ssRNA) hydrolysis by the Cmr2 subunit. Here, we present the structure-function relationship of Cmr-β, unveiling how binding of the target RNA regulates the Cmr2 activities. Cryoelectron microscopy (cryo-EM) analysis revealed the unique subunit architecture of Cmr-β and captured the complex in different conformational stages of the immune response, including the non-cognate and cognate target-RNA-bound complexes. The binding of the target RNA induces a conformational change of Cmr2, which together with the complementation between the 5' tag in the CRISPR RNAs (crRNA) and the 3' antitag of the target RNA activate different configurations in a unique loop of the Cmr3 subunit, which acts as an allosteric sensor signaling the self- versus non-self-recognition. These findings highlight the diverse defense strategies of type III complexes.
全体 : Type III-B Cmr-beta complex bound to non-cognate target RNA
全体
名称: Type III-B Cmr-beta complex bound to non-cognate target RNA
要素
複合体: Type III-B Cmr-beta complex bound to non-cognate target RNA
タンパク質・ペプチド: CRISPR-associated protein, Cmr5 family
タンパク質・ペプチド: CRISPR-associated RAMP protein, Cmr4 family
タンパク質・ペプチド: CRISPR-associated protein, Cmr3 family
タンパク質・ペプチド: CRISPR-associated RAMP protein, Cmr6 family
タンパク質・ペプチド: Cmr1,CRISPR-associated RAMP protein, Cmr1 family,CRISPR-associated RAMP protein, Cmr1 family
タンパク質・ペプチド: CRISPR-associated protein, Cmr2 family
RNA: Non-cognate target RNA
RNA: crRNA
タンパク質・ペプチド: CRISPR-associated protein Cmr7
リガンド: ZINC ION
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超分子 #1: Type III-B Cmr-beta complex bound to non-cognate target RNA
超分子
名称: Type III-B Cmr-beta complex bound to non-cognate target RNA タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1-#9 詳細: A non-cognate target RNA is bound, i.e. the 3'-anti-tag is complementary to the 5' tag of the crRNA. Cmr7 is part of the complex.
名称: Cmr1,CRISPR-associated RAMP protein, Cmr1 family,CRISPR-associated RAMP protein, Cmr1 family タイプ: protein_or_peptide / ID: 5 詳細: The N-terminal "MEEELL" sequence is not part of the annotated sequence (F0NDX4) due to an annotation mistake. コピー数: 1 / 光学異性体: LEVO