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-Structure paper
Title | RNA activation-independent DNA targeting of the Type III CRISPR-Cas system by a Csm complex. |
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Journal, issue, pages | EMBO Rep, Vol. 18, Issue 5, Page 826-840, Year 2017 |
Publish date | Mar 31, 2017 |
Authors | Kwang-Hyun Park / Yan An / Tae-Yang Jung / In-Young Baek / Haemin Noh / Woo-Chan Ahn / Hans Hebert / Ji-Joon Song / Jeong-Hoon Kim / Byung-Ha Oh / Eui-Jeon Woo / |
PubMed Abstract | The CRISPR-Cas system is an adaptive and heritable immune response that destroys invading foreign nucleic acids. The effector complex of the Type III CRISPR-Cas system targets RNA and DNA in a ...The CRISPR-Cas system is an adaptive and heritable immune response that destroys invading foreign nucleic acids. The effector complex of the Type III CRISPR-Cas system targets RNA and DNA in a transcription-coupled manner, but the exact mechanism of DNA targeting by this complex remains elusive. In this study, an effector Csm holocomplex derived from is reconstituted with a minimalistic combination of Csm12345, and shows RNA targeting and RNA-activated single-stranded DNA (ssDNA) targeting activities. Unexpectedly, in the absence of an RNA transcript, it cleaves ssDNA containing a sequence complementary to the bound crRNA guide region in a manner dependent on the HD domain of the Csm1 subunit. This nuclease activity is blocked by a repeat tag found in the host CRISPR loci. The specific cleavage of ssDNA without a target RNA suggests a novel ssDNA targeting mechanism of the Type III system, which could facilitate the efficient and complete degradation of foreign nucleic acids. |
External links | EMBO Rep / PubMed:28364023 / PubMed Central |
Methods | EM (single particle) |
Resolution | 25.0 Å |
Structure data | EMDB-3454: |
Source |
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