Protein
CRISPR-associated exonuclease Csa1
Organism
Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)
Function
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) (By similarity). A ssDNA exonuclease that has both 5' to 3' and 3' to 5' activity, yielding 5'-OH and 3'-phosphate groups. Has Mn(2+)-dependent endonuclease activity on circular ssDNA. Can unwind dsDNA; unwinding does not require ATP.
Similarity
Belongs to the CRISPR-associated protein Csa1 family.
Sequence
MFFTHSDMLLLSKRIKKLPKNVDEELRGWNWSEPPVYTRSLSQVSISEMVYCSTLRNVYLKVKGFRGEIGRQILQGSLIHTIYAIGIEAIKRFIYSRESIDGSTLRTLMGDEFYSLLKDLREEEGIYAKVLWDHITNIYSAELDRVRSKFTNLTRDSLVSQVVPFYVEFPVDGSLLGLTNLRVDAFIPHLPLIAEMKTGKYRYTHELSLAGYALAIESQYEIPIDFGYLCYVTVTEKEVKNNCKLIPISDSLRSEFLDMRDKAQDIMDKGVDPGIAKDCESDCMFYKVCHP