Cas6b, C-terminal domain (IPR020209)

Short name: Cas6b_C

Overlapping homologous superfamilies


Domain relationships



Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci play a pivotal role in the prokaryotic host defense system against invading genetic materials. The CRISPR loci are transcribed to produce CRISPR RNAs (crRNAs), which form interference complexes with CRISPR-associated (Cas) proteins to target the invading nucleic acid for degradation [PMID: 25451598]. Four Cas proteins (Cas5, Cas6b, Cas7 and Cas8b) are proposed to form a Type I-B Cascade complex that mediates the antiviral defense [PMID: 28238733].

This is the C-terminal domain found in Cas6b proteins. Cas6b is a member of Cas6 RNA processing endoribonucleases found in bacteria and archaea whose RNA substrates have a wide range of structural features. Crystal structures of Cas6 from Methanococcus maripaludis (MmCas6b) bound with its repeat RNA revealed a dual-site binding structure and a cleavage site conformation poised for phosphodiester bond breakage [PMID: 26996962].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.