title: Crystal structure of Streptococcus pyogenes Csn2 reveals calcium-dependent conformational changes in its tertiary and quaternary structure.
abstract: Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute a microbial immune system against invading genetic elements, such as plasmids and phages. Csn2 is an Nmeni subtype-specific Cas protein, and was suggested to function in the adaptation process, during which parts of foreign nucleic acids are integrated into the host microbial genome to enable immunity against future invasion. Here, we report a 2.2 Å crystal structure of Streptococcus pyogenes Csn2. The structure revealed previously unseen calcium-dependent conformational changes in its tertiary and quaternary structure. This supports the proposed double-stranded DNA-binding function of S. pyogenes Csn2.
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.
authors.forename: Yoon
authors.initials: Y
authors.lastname: Koo
authors.forename: Du-kyo
authors.initials: DK
authors.lastname: Jung
authors.forename: Euiyoung
authors.initials: E
authors.lastname: Bae
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002118:Calcium / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D008670:Metals / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013297:Streptococcus pyogenes / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008670:Metals; D004247:DNA; D002118:Calcium