title: RNA in defense: CRISPRs protect prokaryotes against mobile genetic elements.
abstract: The CRISPR/Cas system in prokaryotes provides resistance against invading viruses and plasmids. Three distinct stages in the mechanism can be recognized. Initially, fragments of invader DNA are integrated as new spacers into the repetitive CRISPR locus. Subsequently, the CRISPR is transcribed and the transcript is cleaved by a Cas protein within the repeats, generating short RNAs (crRNAs) that contain the spacer sequence. Finally, crRNAs guide the Cas protein machinery to a complementary invader target, either DNA or RNA, resulting in inhibition of virus or plasmid proliferation. In this article, we discuss our current understanding of this fascinating adaptive and heritable defense system, and describe functional similarities and differences with RNAi in eukaryotes.
authors: Laboratory of Microbiology, Wageningen University, Netherlands.
authors: Matthijs M
authors: MM
authors: Jore
authors: Stan J J
authors: SJ
authors: Brouns
authors: John
authors: J
authors: van der Oost
mesh_terms: D001483:Base Sequence; D004251:DNA Transposable Elements; D008958:Models, Molecular; D011387:Prokaryotic Cells; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D004251:DNA Transposable Elements; D012333:RNA, Messenger