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-Structure paper
タイトル | Structural biology. Structures of the CRISPR-Cmr complex reveal mode of RNA target positioning. |
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ジャーナル・号・ページ | Science, Vol. 348, Issue 6234, Page 581-585, Year 2015 |
掲載日 | 2015年5月1日 |
著者 | David W Taylor / Yifan Zhu / Raymond H J Staals / Jack E Kornfeld / Akeo Shinkai / John van der Oost / Eva Nogales / Jennifer A Doudna / |
PubMed 要旨 | Adaptive immunity in bacteria involves RNA-guided surveillance complexes that use CRISPR (clustered regularly interspaced short palindromic repeats)-associated (Cas) proteins together with CRISPR ...Adaptive immunity in bacteria involves RNA-guided surveillance complexes that use CRISPR (clustered regularly interspaced short palindromic repeats)-associated (Cas) proteins together with CRISPR RNAs (crRNAs) to target invasive nucleic acids for degradation. Whereas type I and type II CRISPR-Cas surveillance complexes target double-stranded DNA, type III complexes target single-stranded RNA. Near-atomic resolution cryo-electron microscopy reconstructions of native type III Cmr (CRISPR RAMP module) complexes in the absence and presence of target RNA reveal a helical protein arrangement that positions the crRNA for substrate binding. Thumblike β hairpins intercalate between segments of duplexed crRNA:target RNA to facilitate cleavage of the target at 6-nucleotide intervals. The Cmr complex is architecturally similar to the type I CRISPR-Cascade complex, suggesting divergent evolution of these immune systems from a common ancestor. |
リンク | Science / PubMed:25837515 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 4.1 - 4.4 Å |
構造データ | EMDB-2898: EMDB-2899: EMDB-2900: |
由来 |
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