Unbalanced restriction impairs SOS-induced DNA repair effects.
The contribution of a type II restriction-modification system (R-M system) to genome integrity and cell viability was investigated. We established experimental conditions which enabled the achievement of hemimethylated and unmethylated states for the specific bases of the recognition sequences of the host's DNA. To achieve this, we constructed the MboII R-M system containing only one (i.e. M2.MboII) out of two functional MboII methyltransferases found in Moraxella bovis. Using the incomplete R-M system we were able to perturb the balance between methylation and restriction in an inducible manner. We demonstrate that upon the SOS-induced DNA repair in the mitomycin C treated cells, restriction significantly reduces cell viability. Similar results for the well-studied wild type EcoRI R-M system, expressed constitutively in Escherichia coli, were obtained. Our data provide further insights into the benefits and disadvantages of maintaining of a type II R-M system, highlighting its impact on host cell fitness.
Department of Microbiology, University of Gdansk, 80-822 Gdansk, Kladki 24, Poland.
Anna
A
Katna
Robert
R
Boratynski
Beata
B
Furmanek-Blaszk
Natalia
N
Zolcinska
Marian
M
Sektas
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D019175:DNA Methylation; D004260:DNA Repair; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D016955:Moraxella bovis / Q000201:enzymology; D013014:SOS Response, Genetics; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D015280:DNA Restriction-Modification Enzymes; C047058:DNA modification methylase MboII; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)