[2018] Molecular organization of the type II-A CRISPR adaptation module and its interaction with Cas9 via Csn2
Journal
Nucleic Acids Res 46(18): 9805-9815
Authors
Ka, D., Jang, D.M., Han, B.W. and Bae, E.*
*Denotes Corresponding Author
Abstract
Journal
Nucleic Acids Res 46(18): 9805-9815
Authors
Ka, D., Jang, D.M., Han, B.W. and Bae, E.*
*Denotes Corresponding Author
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins provide microbial adaptive immunity against invading foreign nucleic acids. In type II-A CRISPR-Cas systems, the Cas1-Cas2 integrase complex and the subtype-specific Csn2 comprise the CRISPR adaptation module, which cooperates with the Cas9 nuclease effector for spacer selection. Here, we report the molecular organization of the Streptococcus pyogenes type II-A CRISPR adaptation module and its interaction with Cas9 via Csn2. We determined the crystal structure of S. pyogenes type II-A Cas2. Chromatographic and calorimetric analyses revealed the stoichiometry and topology of the type II-A adaptation module composed of Cas1, Cas2 and Csn2. We also demonstrated that Cas9 interacts with Csn2 in a direct and stoichiometric manner. Our results reveal a network of molecular interactions among type II-A Cas proteins and highlight the role of Csn2 in coordinating Cas components involved in the adaptation and interference stages of CRISPR-mediated immunity.