Structural biology. Crystal structure of the CRISPR RNA-guided surveillance complex from Escherichia coli.
Loading...
Date
Journal Title
Journal ISSN
Volume Title
Publisher
American Association for the Advancement of Science (AAAS)
https://doi.org/10.1126/science.1256328
https://doi.org/10.1126/science.1256328
Abstract
Description
Clustered regularly interspaced short palindromic repeats (CRISPRs) are essential components of RNA-guided adaptive immune systems that protect bacteria and archaea from viruses and plasmids. In Escherichia coli, short CRISPR-derived RNAs (crRNAs) assemble into a 405-kilodalton multisubunit surveillance complex called Cascade (CRISPR-associated complex for antiviral defense). Here we present the 3.24 angstrom resolution x-ray crystal structure of Cascade. Eleven proteins and a 61-nucleotide crRNA assemble into a seahorse-shaped architecture that binds double-stranded DNA targets complementary to the crRNA-guide sequence. Conserved sequences on the 3' and 5' ends of the crRNA are anchored by proteins at opposite ends of the complex, whereas the guide sequence is displayed along a helical assembly of six interwoven subunits that present five-nucleotide segments of the crRNA in pseudo-A-form configuration. The structure of Cascade suggests a mechanism for assembly and provides insights into the mechanisms of target recognition.
This is the author's accepted manuscript and will be under embargo until the 7th of February 2015. The final version is published in Science here: http://www.sciencemag.org/content/early/2014/08/06/science.1256328.abstract.
This is the author's accepted manuscript and will be under embargo until the 7th of February 2015. The final version is published in Science here: http://www.sciencemag.org/content/early/2014/08/06/science.1256328.abstract.