8FLJ

Cas1-Cas2/3 integrase and IHF bound to CRISPR leader, repeat and foreign DNA

Summary for 8FLJ

• Entry DOI: 10.2210/pdb8flj/pdb
• EMDB information: 29280
• Descriptor: CRISPR-associated endonuclease Cas1, Integration host factor subunit alpha, Integration host factor subunit beta, ... (8 entities in total)
• Functional Keywords: dna integration, maintenance of crispr repeat elements, ihf-dna complex, enzymes altering nucleic acid conformation, site specific endodeoxyribonucleases: cleavage is not sequence specific, nucleotidyltransferases, go:0008301, recombination, dna binding protein, hydrolase-dna complex, hydrolase/dna
• Biological source: Pseudomonas aeruginosa PA14; More
• Total number of polymer chains: 14
• Total formula weight: 562661.58

Authors

Santiago-Frangos, A.,Henriques, W.S.,Wiegand, T.,Gauvin, C.,Buyukyoruk, M.,Neselu, K.,Eng, E.T.,Lander, G.C.,Wiedenheft, B. (deposition date: 2022-12-21, release date: 2023-09-06, Last modification date: 2023-11-22)

Primary citation

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.
Structure reveals why genome folding is necessary for site-specific integration of foreign DNA into CRISPR arrays.
Nat.Struct.Mol.Biol., 30:1675-1685, 2023

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.

PubMed: 37710013
DOI: 10.1038/s41594-023-01097-2

Experimental method

ELECTRON MICROSCOPY (3.48 Å)