CRISPR-based immune systems of the Sulfolobales: complexity and diversity.
CRISPR (cluster of regularly interspaced palindromic repeats)/Cas and CRISPR/Cmr systems of Sulfolobus, targeting DNA and RNA respectively of invading viruses or plasmids are complex and diverse. We address their classification and functional diversity, and the wide sequence diversity of RAMP (repeat-associated mysterious protein)-motif containing proteins encoded in Cmr modules. Factors influencing maintenance of partially impaired CRISPR-based systems are discussed. The capacity for whole CRISPR transcripts to be generated despite the uptake of transcription signals within spacer sequences is considered. Targeting of protospacer regions of invading elements by Cas protein-crRNA (CRISPR RNA) complexes exhibit relatively low sequence stringency, but the integrity of protospacer-associated motifs appears to be important. Different mechanisms for circumventing or inactivating the immune systems are presented.
Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200N Copenhagen K, Denmark. garrett@bio.ku.dk
Roger A
RA
Garrett
Shiraz A
SA
Shah
Gisle
G
Vestergaard
Ling
L
Deng
Soley
S
Gudbergsdottir
Chandra S
CS
Kenchappa
Susanne
S
Erdmann
Qunxin
Q
She
D019843:Archaeal Proteins / Q000145:classification / Q000235:genetics / Q000276:immunology; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics / Q000276:immunology; D021901:DNA, Intergenic; D004279:DNA, Viral / Q000235:genetics / Q000276:immunology; D007109:Immunity / Q000235:genetics*; D055029:Inverted Repeat Sequences; D008969:Molecular Sequence Data; D016942:Sulfolobales / Q000235:genetics* / Q000276:immunology*
D019843:Archaeal Proteins; D004269:DNA, Bacterial; D021901:DNA, Intergenic; D004279:DNA, Viral