title: Dual nuclease activity of a Cas2 protein in CRISPR-Cas subtype I-B of Leptospira interrogans.
abstract: Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 carries a set of cas genes associated with CRISPR-Cas subtype I-B. Herein, we report for the first time active transcription of a set of cas genes (cas1 to cas8) of L. interrogans where cas4, cas1, cas2 and cas6, cas3, cas8, cas7, cas5 are clustered together in two independent operons. As an initial step toward comprehensive understanding of CRISPR-Cas system in spirochete, the biochemical study of one of the core Leptospira Cas2 proteins (Lep_Cas2) showed nuclease activity on both DNA and RNA in a nonspecific manner. Additionally, unlike other known Cas2 proteins, Lep_Cas2 showed metal-independent RNase activity and preferential activity on RNA over DNA. These results provide insight for understanding Cas2 diversity existing in the prokaryotic adaptive immune system.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, India.
authors.forename: Bhuvan
authors.initials: B
authors.lastname: Dixit
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, India.
authors.forename: Karukriti Kaushik
authors.initials: KK
authors.lastname: Ghosh
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, India.
authors.forename: Gary
authors.initials: G
authors.lastname: Fernandes
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, India.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, India.
authors.forename: Prerana
authors.initials: P
authors.lastname: Gogoi
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, India.
authors.forename: Manish
authors.initials: M
authors.lastname: Kumar
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D064113:CRISPR-Cas Systems; D019295:Computational Biology; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D030562:Databases, Protein; D004720:Endonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism; D005103:Expert Systems; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007921:Leptospira interrogans / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017354:Point Mutation; D011487:Protein Conformation; D012329:RNA, Bacterial / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D007527:Isoenzymes; D012329:RNA, Bacterial; D011994:Recombinant Proteins; D004720:Endonucleases
keywords: CRISPR-Cas; Cas protein; Leptospira; RNase; nucleases