Structure of the Saccharolobus solfataricus type III-D CRISPR effector
Abstract
CRISPR-Cas is a prokaryotic adaptive immune system, classified into six different types, each characterised by a signature protein. Type III systems, classified based on the presence of a Cas10 subunit, are rather diverse multi- subunit assemblies with a range of enzymatic activities and downstream ancillary effectors. The broad array of current biotechnological CRISPR applications is mainly based on proteins classified as Type II, however recent developments established the feasibility and efficacy of multi-protein Type III CRISPR-Cas effector complexes as RNA-targeting tools in eukaryotes. The crenarchaeon Saccharolobus solfataricus has two type III system subtypes (III- B and III-D). Here, we report the cryo-EM structure of the Csm Type III-D complex from S. solfataricus (SsoCsm), which uses CRISPR RNA to bind target RNA molecules, activating the Cas10 subunit for antiviral defence. The structure reveals the complex organisation, subunit/subunit connectivity and protein/guide RNA interactions of the SsoCsm complex, one of the largest CRISPR effectors known.
Citation
Cannone , G , Kompaniiets , D , Graham , S , White , M & Spagnolo , L 2023 , ' Structure of the Saccharolobus solfataricus type III-D CRISPR effector ' , Current Research in Structural Biology , vol. 5 , 100098 . https://doi.org/10.1016/j.crstbi.2023.100098
Publication
Current Research in Structural Biology
Status
Peer reviewed
ISSN
2665-928XType
Journal article
Rights
Copyright © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Description
Funding: The authors acknowledge funding from BBSRC BB/J005673/1 project grant to LS and MFW and ERC funding to MFW (grant ref 101018608). DK was funded by a Darwin Trust of Edinburgh grant. We acknowledge Diamond Light Source for access and support of the cryo-EM facilities at the UK's national Electron Bio-imaging Centre (eBIC) under proposal EM16637-14, funded by the Wellcome Trust, MRC and BBRSC. The Scottish Centre for Macromolecular Imaging (SCMI) is funded by the MRC (MC_PC_17135) and SFC (H17007).Collections
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