CRISPR RNA binding drives structural ordering that primes Cas7-11 for target cleavage.

ABSTRACT: Type III-E CRISPR-Cas effectors, referred to as Cas7-11 or giant Repeat-Associated Mysterious Protein, are single proteins that cleave target RNAs (tgRNAs) without nonspecific collateral cleavage, opening new possibilities for RNA editing. Here, biochemical assays combined with amide hydrogen-deuterium exchange mass spectrometry (HDX-MS) experiments reveal the dynamics of apo Cas7-11. The HDX-MS results suggest a mechanism by which CRISPR RNA (crRNA) stabilizes the folded state of the protein and subsequent tgRNA binding remodels it to the active form. HDX-MS shows that the four Cas7 RNA recognition motif (RRM) folds are well-folded, but insertion sequences, including disordered catalytic loops and β-hairpins of the Cas7.2/Cas7.3 active sites, fold upon binding crRNA leading to stronger in

SUBMITTER: Lin CP 

PROVIDER: S-EPMC11995262 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature