Mutational Analysis of the Antitoxin in the Lactococcal Type III Toxin-Antitoxin System AbiQ.

ABSTRACT: The lactococcal abortive phage infection mechanism AbiQ recently was classified as a type III toxin-antitoxin system in which the toxic protein (ABIQ) is regulated following cleavage of its repeated noncoding RNA antitoxin (antiQ). In this study, we investigated the role of the antitoxin in antiphage activity. The cleavage of antiQ by ABIQ was characterized using 5' rapid amplification of cDNA ends PCR and was located in an adenine-rich region of antiQ. We next generated a series of derivatives with point mutations within antiQ or with various numbers of antiQ repetitions. These modifications were analyzed for their effect on the antiphage activity (efficiency of plaquing) and on the endoribonuclease activity (Northern hybridization). We observed that increasing or reducing the number of a

SUBMITTER: Belanger M 

PROVIDER: S-EPMC4421047 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature