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Publication Abstract from PubMed

A multi-subunit ribonucleoprotein complex termed the Cmr RNA-silencing complex recognizes and destroys viral RNA in the CRISPR-mediated immune defence mechanism in many prokaryotes using an as yet unclear mechanism. In Archaeoglobus fulgidus, this complex consists of six subunits, Cmr1-Cmr6. Here, the crystal structure of Cmr1 from A. fulgidus is reported, revealing that the protein is composed of two tightly associated ferredoxin-like domains. The domain located at the N-terminus is structurally most similar to the N-terminal ferredoxin-like domain of the CRISPR RNA-processing enzyme Cas6 from Pyrococcus furiosus. An ensuing mutational analysis identified a highly conserved basic surface patch that binds single-stranded nucleic acids specifically, including the mature CRISPR RNA, but in a sequence-independent manner. In addition, this subunit was found to cleave single-stranded RNA. Together, these studies elucidate the structure and the catalytic activity of the Cmr1 subunit.

Crystal structure and CRISPR RNA-binding site of the Cmr1 subunit of the Cmr interference complex.,Sun J, Jeon JH, Shin M, Shin HC, Oh BH, Kim JS Acta Crystallogr D Biol Crystallogr. 2014 Feb;70(Pt 2):535-43. doi:, 10.1107/S1399004713030290. Epub 2014 Jan 31. PMID:24531487^[1]

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