A phage protein confers resistance to the lactococcal abortive infection mechanism AbiP

Phage bIL66M1 is sensitive to the lactococcal abortive infection mechanism AbiP. No spontaneous AbiP-resistant variant could be obtained at a frequency of <10(-10). However, AbiP-resistant variants were readily obtained during infection with both bIL66M1 and the highly homologous AbiP-resistant phage bIL170. Gain of AbiP resistance was due to the acquisition of the e6 gene from bIL170.