Download MendeleyStructure reveals why genome folding is necessary for site-specific integration of foreign DNA into CRISPR arrays.
Santiago-Frangos, A., Henriques, W.S., Wiegand, T., Gauvin, C.C., Buyukyoruk, M., Graham, A.B., Wilkinson, R.A., Triem, L., Neselu, K., Eng, E.T., Lander, G.C., Wiedenheft, B.(2023) Nat Struct Mol Biol 30: 1675-1685
- PubMed: 37710013
- DOI: https://doi.org/10.1038/s41594-023-01097-2
- Primary Citation of Related Structures:
8FLJ - PubMed Abstract:
Bacteria and archaea acquire resistance to viruses and plasmids by integrating fragments of foreign DNA into the first repeat of a CRISPR array. However, the mechanism of site-specific integration remains poorly understood. Here, we determine a 560-kDa integration complex structure that explains how Pseudomonas aeruginosa Cas (Cas1-Cas2/3) and non-Cas proteins (for example, integration host factor) fold 150 base pairs of host DNA into a U-shaped bend and a loop that protrude from Cas1-2/3 at right angles. The U-shaped bend traps foreign DNA on one face of the Cas1-2/3 integrase, while the loop places the first CRISPR repeat in the Cas1 active site. Both Cas3 proteins rotate 100 degrees to expose DNA-binding sites on either side of the Cas2 homodimer, which each bind an inverted repeat motif in the leader. Leader sequence motifs direct Cas1-2/3-mediated integration to diverse repeat sequences that have a 5'-GT. Collectively, this work reveals new DNA-binding surfaces on Cas2 that are critical for DNA folding and site-specific delivery of foreign DNA.
Organizational Affiliation:
Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
