crystal structure of streptococcus pyogenes csn2 reveals calcium-dependent conformational changes in its tertiary and quaternary structure晶体结构的酿脓链球菌csn2揭示calcium-dependent构象的变化它的三级和四级结构.pdf

Crystal Structure of Streptococcus pyogenes Csn2 Reveals Calcium-Dependent Conformational Changes in Its Tertiary and Quaternary Structure Yoon Koo1., Du-kyo Jung1., Euiyoung Bae1,2* 1 Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea, 2 Center for Agricultural Biomaterials, Seoul National University, Seoul, South Korea 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 A 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. Citation: Koo Y, Jung D-k, Bae E (2012) Crystal Structure of Streptococcus pyogenes Csn2 Reveals Calcium-Dependent Conformational Changes in Its Tertiary and Quaternary Structure. PLoS ONE 7(3): e33401. doi:10.1371/journal.pone.0033401 Editor: Inari Kursula, Helmholtz Centre for Infection Research, Germany Received September 26, 2011; Accepted February 11, 2012; Published March 30, 2012 Copyright: 2012 Koo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: Th