The CRISPR-Cas system is a prokaryotic defense mechanism against foreign genetic elements. The key elements of this defense system are the Cas proteins and the CRISPR RNA. In the CRISPR-Cas system, RNA is targeted by the CMR complex. In Sulfolobus solfataricus this complex is composed of seven CAS protein subunits (Cmr1-7) and carries a diverse "payload" of targeting crRNA. This entry represent the Cmr7 subunit of the CMR complex [1].

1: Structure and mechanism of the CMR complex for CRISPR-mediated antiviral immunity. Zhang J, Rouillon C, Kerou M, Reeks J, Brugger K, Graham S, Reimann J, Cannone G, Liu H, Albers SV, Naismith JH, Spagnolo L, White MF; Mol Cell. 2012;45:303-313. PMID:22227115