title: Modulation of CRISPR locus transcription by the repeat-binding protein Cbp1 in Sulfolobus.
abstract: CRISPR loci are essential components of the adaptive immune system of archaea and bacteria. They consist of long arrays of repeats separated by DNA spacers encoding guide RNAs (crRNA), which target foreign genetic elements. Cbp1 (CRISPR DNA repeat binding protein) binds specifically to the multiple direct repeats of CRISPR loci of members of the acidothermophilic, crenarchaeal order Sulfolobales. cbp1 gene deletion from Sulfolobus islandicus REY15A produced a strong reduction in pre-crRNA yields from CRISPR loci but did not inhibit the foreign DNA targeting capacity of the CRISPR/Cas system. Conversely, overexpression of Cbp1 in S. islandicus generated an increase in pre-crRNA yields while the level of reverse strand transcripts from CRISPR loci remained unchanged. It is proposed that Cbp1 modulates production of longer pre-crRNA transcripts from CRISPR loci. A possible mechanism is that it minimizes interference from potential transcriptional signals carried on spacers deriving from A-T-rich genetic elements and, occasionally, on DNA repeats. Supporting evidence is provided by microarray and northern blotting analyses, and publicly available whole-transcriptome data for S. solfataricus P2.
authors.affiliation: Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200N Copenhagen K, Denmark.
authors.forename: Ling
authors.initials: L
authors.lastname: Deng
authors.forename: Chandra S
authors.initials: CS
authors.lastname: Kenchappa
authors.forename: Xu
authors.initials: X
authors.lastname: Peng
authors.forename: Qunxin
authors.initials: Q
authors.lastname: She
authors.forename: Roger A
authors.initials: RA
authors.lastname: Garrett
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D019641:DNA, Archaeal / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019848:Gene Expression Regulation, Archaeal; D056426:Genetic Loci; D020411:Oligonucleotide Array Sequence Analysis; D012322:RNA Precursors / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D016944:Sulfolobus / Q000235:genetics* / Q000378:metabolism; D048229:Sulfolobus solfataricus / Q000235:genetics; D014158:Transcription, Genetic; D058727:RNA, Small Untranslated
chemical_list: D019843:Archaeal Proteins; D019641:DNA, Archaeal; D004268:DNA-Binding Proteins; D012322:RNA Precursors; D058727:RNA, Small Untranslated