Naslov
Cas3-stimulated runaway replication of ColE1 plasmids in Escherichia coli is temperature dependent

Autori
Radovčić, Marin ; Čulo, Anja ; Ivančić-Baće, Ivana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
CRISPR2019 / Moineau, Sylvian ; Maxwell, Karen ; Davidson, Alan - Quebec, 2019, 177-177

Skup
CRISPR2019

Mjesto i datum
Quebec, Kanada, 17.06.2019. - 20.06.2019

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
CRISPR-Cas ; H-NS ; HtpG ; ColE1 ; temperature ; Escherichia coli

Sažetak
The CRISPR-Cas system constitutes an adaptive immunity system of prokaryotes against mobile genetic elements using a crRNA-mediated interference mechanism. In Type IE CRISPR-Cas systems crRNA guided by a Cascade complex recognizes the matching target DNA and promotes R-loop formation, an RNA-DNA hybrid. The helicase-nuclease Cas3 protein is then recruited to the Cascade/R-loop complex where it nicks and degrades DNA. In E. coli, the CRISPR-Cas immunity against  phage was shown to be temperature dependent if CRISPR-Cas components were expressed from native promoters in cells lacking H-NS, the repressor of CRISPR locus and cas genes. Cas3 protein can also promote uncontrolled replication of ColE1 plasmids independently of other CRISPR-Cas components, requiring only its helicase activity. We found that Cas3-stimulated uncontrolled plasmid replication occurs only at 37 °C independently of the cell’s genotype. There was no increase of plasmid yields at 30 °C and similar results were observed with a helicase mutant at both temperatures. We also found that plasmid replication was strongly reduced by the hns mutation at 30 °C. Overall, our findings suggest that increased replication of ColE1 plasmids depends on change in ATPase/helicase activity of Cas3 protein which depends on the temperature of incubation.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA