MOLECULAR COMPARISON OF THE STRUCTURAL PROTEINS ENCODING GENE CLUSTERS OF 2 RELATED LACTOBACILLUS-DELBRUECKII BACTERIOPHAGES

Virulent phage LL-H and temperate phage mv4 are two related bacterioph ages of Lactobacillus delbrueckii. The gene clusters encoding structur al proteins of these two phages have been sequenced and further analyz ed. Six open reading frames (ORF-1 to ORF-6) were detected. Protein se quencing and Western immunoblotting experiments confirmed that ORF-3 ( g34) encoded the main capsid protein Gp34. The presence of a putative late promoter in front of the phage LL-H g34 gene was suggested by pri mer extension experiments. Comparative sequence analysis between phage LL-H and phage mv4 revealed striking similarities in the structure an d organization of this gene cluster, suggesting that the genes encodin g phage structural proteins belong to a highly conservative module.