Molecular mechanisms of CRISPR–Cas spacer acquisition

• Published in: Nature reviews. Microbiology Vol. 17; no. 1; pp. 7 - 12
• Main Authors: McGinn, Jon, Marraffini, Luciano A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-01-2019; Nature Publishing Group
• Subjects: 631/326/325; 631/326/41; 631/326/596/432; Archaea; Archaea - genetics; Bacteria - genetics; Biomedical and Life Sciences; Clustered Regularly Interspaced Short Palindromic Repeats - genetics; CRISPR; CRISPR-Cas Systems; Deoxyribonucleic acid; DNA; DNA, Intergenic; Gene expression; Genome; Genomes; Immune response; Immune system; Immunity; Infectious Diseases; Life Sciences; Medical Microbiology; Microbiology; Molecular mechanics; Molecular modelling; Nuclease; Nucleic acids; Parasitology; Progress; RNA sequencing; Spacer; Spacers; Virology
• ISSN: 1740-1526; 1740-1534
• DOI: 10.1038/s41579-018-0071-7

Many bacteria and archaea have the unique ability to heritably alter their genomes by incorporating small fragments of foreign DNA, called spacers, into CRISPR loci. Once transcribed and processed into individual CRISPR RNAs, spacer sequences guide Cas effector nucleases to destroy complementary, invading nucleic acids. Collectively, these two processes are known as the CRISPR–Cas immune response. In this Progress article, we review recent studies that have advanced our understanding of the molecular mechanisms underlying spacer acquisition and that have revealed a fundamental link between the two phases of CRISPR immunity that ensures optimal immunity from newly acquired spacers. Finally, we highlight important open questions and discuss the potential basic and applied impact of spacer acquisition research.
In this Progress article, McGinn and Marraffini review recent studies that have advanced our understanding of the molecular mechanisms of spacer integration, protospacer capture and primed spacer acquisition, and discuss the future of the field.