Download MendeleyCas5d Protein Processes Pre-crRNA and Assembles into a Cascade-like Interference Complex in Subtype I-C/Dvulg CRISPR-Cas System.
Nam, K.H., Haitjema, C., Liu, X., Ding, F., Wang, H., Delisa, M.P., Ke, A.(2012) Structure 20: 1574-1584
- PubMed: 22841292
- DOI: https://doi.org/10.1016/j.str.2012.06.016
- Primary Citation of Related Structures:
4F3M - PubMed Abstract:
Clustered regularly interspaced short palindromic repeats (CRISPRs), together with an operon of CRISPR-associated (Cas) proteins, form an RNA-based prokaryotic immune system against exogenous genetic elements. Cas5 family proteins are found in several type I CRISPR-Cas systems. Here, we report the molecular function of subtype I-C/Dvulg Cas5d from Bacillus halodurans. We show that Cas5d cleaves pre-crRNA into unit length by recognizing both the hairpin structure and the 3' single stranded sequence in the CRISPR repeat region. Cas5d structure reveals a ferredoxin domain-based architecture and a catalytic triad formed by Y46, K116, and H117 residues. We further show that after pre-crRNA processing, Cas5d assembles with crRNA, Csd1, and Csd2 proteins to form a multi-sub-unit interference complex similar to Escherichia coli Cascade (CRISPR-associated complex for antiviral defense) in architecture. Our results suggest that formation of a crRNA-presenting Cascade-like complex is likely a common theme among type I CRISPR subtypes.
Organizational Affiliation:
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
