8ZNS

Type I-C CRISPR-associated protein, Cas3

Summary for 8ZNS

• Entry DOI: 10.2210/pdb8zns/pdb
• Descriptor: CRISPR-associated endonuclease Cas3-HD, FE (III) ION (3 entities in total)
• Functional Keywords: cas3, crispr-cas system, genome editing, nuclease/helicase, dna binding protein, immune system
• Biological source: Neisseria lactamica ATCC 23970
• Total number of polymer chains: 1
• Total formula weight: 96427.22

Authors

Kim, D.Y.,Park, H.H. (deposition date: 2024-05-28, release date: 2024-11-06, Last modification date: 2024-11-27)

Primary citation

Kim, D.Y.,Lee, S.Y.,Ha, H.J.,Park, H.H.
Structural basis of Cas3 activation in type I-C CRISPR-Cas system.
Nucleic Acids Res., 52:10563-10574, 2024

PubMed Abstract: CRISPR-Cas systems function as adaptive immune mechanisms in bacteria and archaea and offer protection against phages and other mobile genetic elements. Among many types of CRISPR-Cas systems, Type I CRISPR-Cas systems are most abundant, with target interference depending on a multi-subunit, RNA-guided complex known as Cascade that recruits a transacting helicase nuclease, Cas3, to degrade the target. While structural studies on several other types of Cas3 have been conducted long ago, it was only recently that the structural study of Type I-C Cas3 in complex with Cascade was revealed, shedding light on how Cas3 achieve its activity in the Cascade complex. In the present study, we elucidated the first structure of standalone Type I-C Cas3 from Neisseria lactamica (NlaCas3). Structural analysis revealed that the histidine-aspartate (HD) nuclease active site of NlaCas3 was bound to two Fe2+ ions that inhibited its activity. Moreover, NlaCas3 could cleave both single-stranded and double-stranded DNA in the presence of Ni2+ or Co2+, showing the highest activity in the presence of both Ni2+ and Mg2+ ions. By comparing the structural studies of various Cas3 proteins, we determined that our NlaCas3 stays in an inactive conformation, allowing us to understand the structural changes associated with its activation and their implication.

PubMed: 39180405
DOI: 10.1093/nar/gkae723

Experimental method

X-RAY DIFFRACTION (2.17 Å)