CRISPR (clustered regularly interspaced short palindromic repeat), is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain sequences complementary to antecedent mobile elements and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA), also called psiRNA (prokaryotic silencing) in this organism. This protein processes pre-crRNA into individual crRNA units, with an 8-nt 5'-repeat DNA tag that may help other proteins recognize the crRNA. Further processing occurs at their 3' termini in this organism. Generates a 5'-hydroxy and 2',3'-cyclic phosphodiester. Does not require a metal cofactor. Optimum temperature is 70 degrees Celsius. Monomer, binds precursor but not mature crRNA; is not part of the Cmr effector complex. Belongs to the CRISPR-associated protein Cas6/Cse3/CasE family.