title: Crystal structure and CRISPR RNA-binding site of the Cmr1 subunit of the Cmr interference complex.
abstract: 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.
authors: Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors: Jiali
authors: J
authors: Sun
authors: Department of Biological Sciences, KAIST Institute for the Biocentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors: Jae-Hyun
authors: JH
authors: Jeon
authors: Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors: Minsang
authors: M
authors: Shin
authors: Department of Biological Sciences, KAIST Institute for the Biocentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors: Ho-Chul
authors: HC
authors: Shin
authors: Department of Biological Sciences, KAIST Institute for the Biocentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors: Byung-Ha
authors: BH
authors: Oh
authors: Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors: Jeong-Sun
authors: JS
authors: Kim
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019611:Archaeoglobus fulgidus / Q000737:chemistry* / Q000276:immunology / Q000821:virology; D001665:Binding Sites; D064112:Clustered Regularly Interspaced Short Palindromic Repeats / Q000235:genetics* / Q000276:immunology; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005288:Ferredoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020027:Pyrococcus furiosus / Q000737:chemistry / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D040681:Structural Homology, Protein; D013379:Substrate Specificity
chemical_list: D019843:Archaeal Proteins; D005288:Ferredoxins; D021122:Protein Subunits; D012367:RNA, Viral; D011994:Recombinant Proteins
keywords: Archaeoglobus fulgidus; Cmr interference complex; Cmr1 subunit; RNA-binding site