title: Genes essential for the morphogenesis of the Shiga toxin 2-transducing phage from Escherichia coli O157:H7.
abstract: 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.
authors.affiliation: Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.|Genetic Engineering and Biotechnology Department, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh.
authors.forename: Shakhinur Islam
authors.initials: SI
authors.lastname: Mondal
authors.affiliation: Biochemistry and Molecular Biology Department, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: Md Rakibul
authors.initials: MR
authors.lastname: Islam
authors.affiliation: Department of Anatomy, Ultrastructural Cell Biology, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sawaguchi
authors.affiliation: Biosafety &BSL3 Laboratory, ICDDR,B, Mahakhali, Dhaka 1212, Bangladesh.
authors.forename: Md
authors.initials: M
authors.lastname: Asadulghani
authors.affiliation: Department of Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
authors.forename: Tadasuke
authors.initials: T
authors.lastname: Ooka
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Gotoh
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Kita 19, Nishi 8, Kita-ku, Sapporo 060-0819, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kasahara
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yoshitoshi
authors.initials: Y
authors.lastname: Ogura
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D001435:Bacteriophages / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D004279:DNA, Viral / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D019453:Escherichia coli O157 / Q000235:genetics* / Q000821:virology; D023061:Gene Order; D020043:Genes, Essential / Q000235:genetics; D005814:Genes, Viral / Q000235:genetics*; D016679:Genome, Viral / Q000235:genetics; D008242:Lysogeny / Q000235:genetics; D016253:Microscopy, Immunoelectron; D009024:Morphogenesis / Q000235:genetics; D009154:Mutation; D017902:Podoviridae / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D022641:Shiga Toxin 2 / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D004279:DNA, Viral; D022641:Shiga Toxin 2; D014764:Viral Proteins; D004706:Endodeoxyribonucleases; C030894:terminase