9W6C

Crystal structure of Cas5IC from Moraxella bovoculi

Summary for 9W6C

• Entry DOI: 10.2210/pdb9w6c/pdb
• Descriptor: crRNA processing protein (1 entity in total)
• Functional Keywords: crispr-cas system, type i-c cas5, rna binding protein, immune system
• Biological source: Moraxella bovoculi
• Total number of polymer chains: 4
• Total formula weight: 113764.42

Authors

Kang, Y.J.,Park, H.H. (deposition date: 2025-08-04, release date: 2026-06-17)

Primary citation

Kang, Y.J.,Ha, H.J.,Jin, H.B.,Lee, S.Y.,Park, H.H.
Structural basis of dimerization and cascade formation by Cas5.
Sci Rep, 16:2976-2976, 2025

PubMed Abstract: CRISPR-Cas systems are essential for prokaryotic adaptive immune mechanisms; however, the structural details of many subtype-specific components remain unclear. Herein, we report the crystal structure and biophysical characterization of Cas5 from Moraxella bovoculi (MboCas5), a component of the type I-C CRISPR-Cas system. We found that M. bovoculi encodes both type I-C and type III-B systems, and that MboCas5 forms a dimer that is stabilized by key interactions, including a salt bridge between R72 and D167. Structural comparisons with other Cas5 homologs and AlphaFold 3 predictions further validated the unique dimer configuration, suggesting that it is conserved across species. Additionally, structural comparison revealed a highly flexible loop region, which likely undergoes conformational changes upon Cascade assembly and might mediate interactions with Cas8 and crRNA. Overall, the findings provided structural and mechanistic insights into Cas5 function and could potentially contribute to our understanding of the assembly of type I-C Cascade complexes.

PubMed: 41398311
DOI: 10.1038/s41598-025-32766-5

Experimental method

X-RAY DIFFRACTION (3.33 Å)