Identification of the repressor-encoding gene of the Lactobacillus bacteriophage A2

Abstract

The repressor gene of the Lactobacillus phage A2 has the following properties: it (i) encodes a 224-residue polypeptide with DNA binding and RecA cleavage motifs, (ii) is expressed in lysogenic cultures, and (iii) confers superinfection immunity on the host. Adjacent, but divergently transcribed, lies another open reading frame whose produce resembles the Å Cro protein. In the 161-bp intergenic segment, putative promoters and operators have been detected.