Complete Genomic Sequence of Bacteriophage φEcoM-GJ1, a Novel Phage That Has Myovirus Morphology and a Podovirus-Like RNA Polymerase

Abstract

The complete genome of φEcoM-GJ1, a lytic phage that attacks porcine enterotoxigenic Escherichia coli of serotype O149:H10:F4, was sequenced and analyzed. The morphology of the phage and the identity of the structural proteins were also determined. The genome consisted of 52,975 bp with a G+C content of 44% and was terminally redundant and circularly permuted. Seventy-five potential open reading frames (ORFs) were identified and annotated, but only 29 possessed homologs. The proteins of five ORFs showed homology with proteins of phages of the family Myoviridae , nine with proteins of phages of the family Podoviridae , and six with proteins of phages of the family Siphoviridae . ORF 1 encoded a T7-like single-subunit RNA polymerase and was preceded by a putative E. coli σ ⁷⁰ -like promoter. Nine putative phage promoters were detected throughout the genome. The genome included a tRNA gene of 95 bp that had a putative 18-bp intron. The phage morphology was typical of phages of the family Myoviridae , with an icosahedral head, a neck, and a long contractile tail with tail fibers. The analysis shows that φEcoM-GJ1 is unique, having the morphology of the Myoviridae , a gene for RNA polymerase, which is characteristic of phages of the T7 group of the Podoviridae , and several genes that encode proteins with homology to proteins of phages of the family Siphoviridae .