Identification of four genes involved in the lysogenic pathway of theSalmonella newington bacterial virus ?34 (original) (raw)
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Virus Genes, 2000
A distinguishing feature of many microorganisms, belonging to the Gram negative group of bacteria, is the presence of the lipopolysaccharide on their cell surface. Salmonella is a prominent member of this group of bacteria. Many Salmonella phages use the LPS as the initial receptor in the infection process and they can distinguish subtle changes in the LPS molecules. The phage protein that is responsible for recognition of these cells is the tail or tailspike protein (TSP). Those TSPs, which use LPS as a receptor, are prokaryotic LPS-binding proteins. As an initial step in using phage TSPs as model systems for a detailed molecular genetic analysis of protein-LPS interactions, a comparison of two phages and their TSPs from two different Salmonella bacterial viruses (phages), Salmonella enterica serovar Typhimurium phage P22 and Salmonella enterica serovar Anatum var. 15+ phage e 34 , is being carried out. This present study shows significant viral protein homology between many viral structural proteins from these two phages including their TSPs. Significantly this report suggests a general structural motif for part of the TSP of phages and suggests that a more detailed comparative analysis of these TSPs is warranted.
Conservation of the N-terminus of some phage tail proteins
Archives of Virology, 2005
To study the interaction between lipopolysaccharide and protein, a comparative approach was employed using seven Salmonella enterica serovar Typhimurium typing phages as the protein model systems. This interaction has been studied in detail in the Salmonella enterica serovar Typhimurium phage P22 system and involves only the viral tailspike protein. Similarity between these phages and phage P22 was monitored in this Report by assaying restriction endonuclease digestions, capsid size, reactivity to the P22 tailspike protein monoclonal antibody, mAb92, which reacts with the N-terminus of the P22 tail protein and the ability to produce a PCR fragment using primers made to the ends of the P22 tailspike gene. The data indicate that tailspike similarity exists between most of these phages and a scheme reclassifying them is presented and that the N-terminus of the P22 tailspike protein may be a motif for many phage systems and may serve as a aid in the taxonomy of phages. The data suggest a classification scheme in which the N-terminus of some tailspike proteins (head-binding regions in some tail proteins) may play a critical element role in the classification of Salmonella viruses. * Currently there has been a resurgence of work on phages . This resurgence is partly fueled by data supporting their importance in disease, potential therapy, horizontal gene transfer and as model systems . A comparison of functionally related proteins has often led to the identification of the functional roles of particular amino acids in polypeptide chains. To better understand how some proteins bind and hydrolyze lipopolysaccharides (LPS), as modeled by the bacterial virus (phage) P22 tailspike protein (TSP) and its
Fems Microbiology Letters, 1998
A smooth colony strain, resistant to phages V and P22, was isolated from sewage and identified as Escherichia coli (strain H). Four temperate phages plaquing on strain H were isolated from sewage. The archetype, HK620, does not plaque on strains C and K12 of E. coli nor on the LT2 strain of Salmonella enterica. Bacterial mutants resistant to a clear plaque mutant of HK620 produce rough colonies. Some are also galactose-negative, a few are histidine auxotrophs, and most show sensitivity to V. HK620 can transduce a wide variety of auxotrophic mutants of E. coli H to prototrophy. It can recombine with V but its virions resemble those of P22.
Microbiology and Molecular Biology Reviews, 2001
SUMMARY Continuous research spanning more than three decades has made the Bacillus bacteriophage φ29 a paradigm for several molecular mechanisms of general biological processes, such as DNA replication, regulation of transcription, phage morphogenesis, and phage DNA packaging. The genome of bacteriophage φ29 consists of a linear double-stranded DNA (dsDNA), which has a terminal protein (TP) covalently linked to its 5′ ends. Initiation of DNA replication, carried out by a protein-primed mechanism, has been studied in detail and is considered to be a model system for the protein-primed DNA replication that is also used by most other linear genomes with a TP linked to their DNA ends, such as other phages, linear plasmids, and adenoviruses. In addition to a continuing progress in unraveling the initiation of DNA replication mechanism and the role of various proteins involved in this process, major advances have been made during the last few years, especially in our understanding of tran...
Characterization of a ViI-like Phage Specific to Escherichia coli O157:H7
Virology Journal, 2011
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 3 H-thymidine (3 H-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 W-14, Bacillus subtilis phage SPO1, and Pseudomonas phage YuA, all known to produce and incorporate hydroxymethyluracil (hmdUra).
Methods in Molecular Biology, 2009
Recent studies have established that the most abundant life form, that of phages, has had major influence on the biosphere, bacterial evolution, bacterial genome, and lateral gene transmission. Importantly the phages have served and continue to serve as valuable model systems. Such studies have led to a renewed interest and activity in the study of phages and their genomes. In order to determine the details of the involvement of phages in these important processes and activities, it is critical to assign specific functions to the phage gene products. The initial functional and gene assignments can be made by general mutagenesis of the phage genomes and of these specific gene products. A very informative mutagenic protocol that has found renewed interest is that using hydroxylamine. This mutagenic protocol has been used to obtain gene mutations involved in the lysogenic cycle of the Salmonella enterica serovar Anatum var. 15+ phage ε 34 (hereafter phage ε 34 ) and to isolate conditional lethal mutants of phage ε 34 . A similar protocol using plasmid is also described. A plate complementation method is presented to determine quickly the number of genes which are present in the population of mutations isolated from hydroxylamine mutagenesis.
Fine Structure Genetic and Physical Map of the Phage P22 Tail Protein Gene
Bacteriophage P22 which are incapable of making functional tail protein can be propagated by the addition of purified mature tail protein trimers to either liquid or solidified medium. This unique in vitro complementation condition has allowed us to isolate 74 absolute lethal tail protein mutants of P22 after hydroxylamine mutagenesis. These phage mutants have an absolute requirement for purified P22 tail protein to be present in a soft agar overlay in order to form plaques and do not grow on any nonsense suppressing strains of Salmonella typhimurium. In order to genetically map and physically locate these mutations we have constructed two complementary sets of fine structure deletion mapping strains using a collection of Tnl insertions in gene 9, the structural gene for the tail protein. Fourteen bacteriophage P22 strains carrying unique Tnl transposon insertions (Ap phage) in gene 9 have been crossed with Ap phage carrying Tnl insertions in gene 20. Phage carrying deletions that a...
S2.0 S0092867401006377 main Phage Genomics: Small Is Beautiful
genes. These genetic functions can be squeezed into a Nestec Ltd. 20 kb DNA genome as demonstrated by c2 Siphovirus Vers-chez-les-Blanc and φ29 Podovirus. As the genome size increases, the CH-1000 Lausanne 26 virion morphology gets more complicated, and the Switzerland phage interferes more with cellular activities. However, 2 Pittsburgh Bacteriophage Institute and we are far from understanding this in detail. Despite Department of Biological Sciences decades of research, only about 130 from the estimated University of Pittsburgh 230 genes of Myovirus T4 have assigned functions. Pittsburgh, Pennsylvania 15260 Tailed phages have been described in many phylogenetic divisions of Eubacteria. Curiously, viruses from All the world's a phage. one branch of Archaea (Euryarchaeota) resemble tailed -W. Shakespeare phages in morphology and genome organization (Pfister et al., 1998). There is also evidence for shared protein There are