Protein
CRISPR-associated endonuclease Cas6/Csy4
Organism
Pseudomonas aeruginosa (strain UCBPP-PA14)
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). Processes pre-crRNA into individual crRNA units. Absolutely required for crRNA production or stability. Upon expression in E.coli endonucleolytically processes pre-crRNA, although disruption and reconstitution experiments indicate that in situ other genes are also required for processing. Yields 5'-hydroxy and 3'-phosphate groups. The Csy ribonucleoprotein complex binds target ssDNA with high affinity but target dsDNA with much lower affinity.
Similarity
Belongs to the CRISPR-associated endoribonuclease Cas6 family. Cas6f/Csy4, subtype I-F/Ypest subfamily.
Sequence
MDHYLDIRLRPDPEFPPAQLMSVLFGKLHQALVAQGGDRIGVSFPDLDESRSRLGERLRIHASADDLRALLARPWLEGLRDHLQFGEPAVVPHPTPYRQVSRVQAKSNPERLRRRLMRRHDLSEEEARKRIPDTVARALDLPFVTLRSQSTGQHFRLFIRHGPLQVTAEEGGFTCYGLSKGGFVPWF