title: Characterization of a ViI-like phage specific to Escherichia coli O157:H7.
abstract: Phage vB_EcoM_CBA120 (CBA120), isolated against Escherichia coli O157:H7 from a cattle feedlot, is morphologically very similar to the classic phage ViI of Salmonella enterica serovar Typhi. Until recently, little was known genetically or physiologically about the ViI-like phages, and none targeting E. coli have been described in the literature. The genome of CBA120 has been fully sequenced and is highly similar to those of both ViI and the Shigella phage AG3. The core set of structural and replication-related proteins of CBA120 are homologous to those from T-even phages, but generally are more closely related to those from T4-like phages of Vibrio, Aeromonas and cyanobacteria than those of the Enterobacteriaceae. The baseplate and method of adhesion to the host are, however, very different from those of either T4 or the cyanophages. None of the outer baseplate proteins are conserved. Instead of T4's long and short tail fibers, CBA120, like ViI, encodes tail spikes related to those normally seen on podoviruses. The 158 kb genome, like that of T4, is circularly permuted and terminally redundant, but unlike T4 CBA120 does not substitute hmdCyt for cytosine in its DNA. However, in contrast to other coliphages, CBA120 and related coliphages we have isolated cannot incorporate 3H-thymidine (3H-dThd) into their DNA. Protein sequence comparisons cluster the putative "thymidylate synthase" of CBA120, ViI and AG3 much more closely with those of Delftia phage φW-14, Bacillus subtilis phage SPO1, and Pseudomonas phage YuA, all known to produce and incorporate hydroxymethyluracil (hmdUra).
authors: The Evergreen State College, Olympia, WA, USA. kutterb@evergreen.edu
authors: Elizabeth M
authors: EM
authors: Kutter
authors: Kyobi
authors: K
authors: Skutt-Kakaria
authors: Bob
authors: B
authors: Blasdel
authors: Ayman
authors: A
authors: El-Shibiny
authors: Anna
authors: A
authors: Castano
authors: Daniel
authors: D
authors: Bryan
authors: Andrew M
authors: AM
authors: Kropinski
authors: Andre
authors: A
authors: Villegas
authors: Hans-Wolfgang
authors: HW
authors: Ackermann
authors: Ana L
authors: AL
authors: Toribio
authors: Derek
authors: D
authors: Pickard
authors: Hany
authors: H
authors: Anany
authors: Todd
authors: T
authors: Callaway
authors: Andrew D
authors: AD
authors: Brabban
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002417:Cattle; D003090:Coliphages / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism; D019295:Computational Biology; D016172:DNA Fingerprinting; D019453:Escherichia coli O157 / Q000502:physiology / Q000821:virology*; D016679:Genome, Viral; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA; D013936:Thymidine / Q000032:analysis / Q000378:metabolism; D014316:Tritium / Q000032:analysis / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication / Q000502:physiology
chemical_list: D011135:Polysaccharides, Bacterial; D014764:Viral Proteins; D014316:Tritium; D013936:Thymidine