Publication Date:
2015-04-04
Description:
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 beta 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.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4582657/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4582657/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Taylor, David W -- Zhu, Yifan -- Staals, Raymond H J -- Kornfeld, Jack E -- Shinkai, Akeo -- van der Oost, John -- Nogales, Eva -- Doudna, Jennifer A -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2015 May 1;348(6234):581-5. doi: 10.1126/science.aaa4535. Epub 2015 Apr 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA. California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA. ; Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, 6703 HB Wageningen, Netherlands. ; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA. ; RIKEN SPring-8 Center, Hyogo 679-5148, Japan. RIKEN Structural Biology Laboratory, Kanagawa 230-0045, Japan. ; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA. California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA. Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA. Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. doudna@berkeley.edu enogales@lbl.gov. ; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA. California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA. Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA. Department of Chemistry, University of California, Berkeley, CA 94720, USA. Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. doudna@berkeley.edu enogales@lbl.gov.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25837515" target="_blank"〉PubMed〈/a〉
Keywords:
*Clustered Regularly Interspaced Short Palindromic Repeats
;
Cryoelectron Microscopy
;
Multiprotein Complexes/*chemistry/ultrastructure
;
RNA/*chemistry/ultrastructure
;
*RNA Cleavage
;
Thermus thermophilus/*immunology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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