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) (By similarity). Functions in an unknown fashion to stimulate transcription of fruA independently of the intracellular A- and E-developmental signals. Operon expression begins by 6 hours after starvation has initiated development and is under strong negative regulation by DevS. Part of an operon going from at least MXAN_7266 to MXAN_7259 that includes a CRISPR operon with transcription continuing into the pre-crRNA locus. Decreases sporulation 1000 to 10000-fold, aggregation is delayed. Delays for C-signal-dependent methylation of FrczCD and impairs fruA transcription. This mutant should not have polar effects on downstream genes. Belongs to the CRISPR-associated protein Cas8a1/Csx13 family. Myxan subtype subfamily.