Digests double-stranded RNA. Involved in the processing of primary rRNA transcript to yield the immediate precursors to the large and small rRNAs (23S and 16S). Also processes some mRNAs, and tRNAs when they are encoded in the rRNA operon (By similarity). 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 spacers, sequences complementary to antecedent mobile elements, and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA). In this organism endogenous ribonuclease 3 and Cas9 are required for correct coprocessing of pre-crRNA and the trans-encoded small RNA (tracrRNA). Cas9, crRNA and tracrRNA are required for cleavage of invading DNA (Probable). Complements pre-crRNA and tracRNA coprocessing defects in an rnc deletion in S.pyogenes strain 370 (PubMed:24270795). Endonucleolytic cleavage to 5'-phosphomonoester. Homodimer. Belongs to the ribonuclease III family.