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-Structure paper
タイトル | Structural basis for self-cleavage prevention by tag:anti-tag pairing complementarity in type VI Cas13 CRISPR systems. |
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ジャーナル・号・ページ | Mol Cell, Vol. 81, Issue 5, Page 1100-11115.e5, Year 2021 |
掲載日 | 2021年3月4日 |
著者 | Beibei Wang / Tianlong Zhang / Jun Yin / You Yu / Wenhao Xu / Jianping Ding / Dinshaw J Patel / Hui Yang / |
PubMed 要旨 | Bacteria and archaea apply CRISPR-Cas surveillance complexes to defend against foreign invaders. These invading genetic elements are captured and integrated into the CRISPR array as spacer elements, ...Bacteria and archaea apply CRISPR-Cas surveillance complexes to defend against foreign invaders. These invading genetic elements are captured and integrated into the CRISPR array as spacer elements, guiding sequence-specific DNA/RNA targeting and cleavage. Recently, in vivo studies have shown that target RNAs with extended complementarity with repeat sequences flanking the target element (tag:anti-tag pairing) can dramatically reduce RNA cleavage by the type VI-A Cas13a system. Here, we report the cryo-EM structure of Leptotrichia shahii LshCas13a in complex with target RNA harboring tag:anti-tag pairing complementarity, with the observed conformational changes providing a molecular explanation for inactivation of the composite HEPN domain cleavage activity. These structural insights, together with in vitro biochemical and in vivo cell-based assays on key mutants, define the molecular principles underlying Cas13a's capacity to target and discriminate between self and non-self RNA targets. Our studies illuminate approaches to regulate Cas13a's cleavage activity, thereby influencing Cas13a-mediated biotechnological applications. |
リンク | Mol Cell / PubMed:33472057 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.06 Å |
構造データ | EMDB-30767, PDB-7dmq: |
由来 |
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キーワード | IMMUNE SYSTEM/RNA / Type VI-A CRISPR-Cas system / Cas13a / anti-tag RNA / inhibition / IMMUNE SYSTEM / IMMUNE SYSTEM-RNA complex |