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Publication Abstract from PubMed

The recently discovered type III-E CRISPR-Cas effector Cas7-11 shows promise when used as an RNA manipulation tool, but its structure and the mechanisms underlying its function remain unclear. Here we present four cryo-EM structures of Desulfonema ishimotonii Cas7-11-crRNA complex in pre-target and target RNA-bound states, and the cryo-EM structure of DiCas7-11-crRNA bound to its accessory protein DiCsx29. These data reveal structural elements for pre-crRNA processing, target RNA cleavage and regulation. Moreover, a 3' seed region of crRNA is involved in regulating RNA cleavage activity of DiCas7-11-crRNA-Csx29. Our analysis also shows that both the minimal mismatch of 4 nt to the 5' handle of crRNA and the minimal matching of the first 12 nt of the spacer by the target RNA are essential for triggering the protease activity of DiCas7-11-crRNA-Csx29 towards DiCsx30. Taken together, we propose that target RNA recognition and cleavage regulate and fine-tune the protease activity of DiCas7-11-crRNA-Csx29, thus preventing auto-immune responses.

Cryo-EM structure and protease activity of the type III-E CRISPR-Cas effector.,Huo Y, Zhao H, Dong Q, Jiang T Nat Microbiol. 2023 Mar;8(3):522-532. doi: 10.1038/s41564-022-01316-4. Epub 2023 , Jan 26. PMID:36702942^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.