Open AccessGenes essential for the morphogenesis of the Shiga toxin 2-transducing phage from Escherichia coli O157:H7
Author(s) -
Shakhinur Islam Mondal,
Rakibul Islam,
Akira Sawaguchi,
Asadulghani,
Tadasuke Ooka,
Yasuhiro Gotoh,
Yasuhiro Kasahara,
Tetsuya Hayashi
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep39036
Subject(s) - biology , podoviridae , lysogenic cycle , gene , virulence , shiga toxin , escherichia coli , bacteriophage , genetics , microbiology and biotechnology , virology
Shiga toxin 2 (Stx2), one of the most important virulence factors of enterohaemorrhagic Escherichia coli (EHEC), is encoded by phages. These phages (Stx2 phages) are often called lambda-like. However, most Stx2 phages are short-tailed, thus belonging to the family Podoviridae , and the functions of many genes, especially those in the late region, are unknown. In this study, we performed a systematic genetic and morphological analysis of genes with unknown functions in Sp5, the Stx2 phage from EHEC O157:H7 strain Sakai. We identified nine essential genes, which, together with the terminase genes, determine Sp5 morphogenesis. Four of these genes most likely encoded portal, major capsid, scaffolding and tail fiber proteins. Although exact roles/functions of the other five genes are unknown, one was involved in head formation and four were required for tail formation. One of the four tail genes encoded an unusually large protein of 2,793 amino-acid residues. Two genes that are likely required to maintain the lysogenic state were also identified. Because the late regions of Stx2 phages from various origins are highly conserved, the present study provides an important basis for better understanding the biology of this unique and medically important group of bacteriophages.