| the genome of the pseudo t-even bacteriophages, a diverse group that resembles t4. | polymerase chain reaction analysis of a large collection of bacteriophages with t-even morphology revealed four phages that are distantly related to all the others. the genomes of these pseudo t-even phages hybridized under stringent conditions to only a limited portion of the t4 genome that encodes virus head, head-to-tail joining and contractile tail genes. except for this region, no extensive hybridization was detected between most pairs of the different pseudo t-even genomes. sequencing of t ... | 1997 | 9096222 |
| cloning and sequencing of major capsid protein (mcp) gene of a vibriophage, kvp20, possibly related to t-even coliphages. | a large, tailed, prolate-headed vibriophage designated kvp20 was isolated from seawater. kvp20 was morphologically very similar to the previously described vibriophage, kvp40 (matsuzaki, s., inoue, t., tanaka, s., 1998. virology, 242, 314-318). however, they showed entirely different host specificities and could easily be differentiated from each other by their patterns of dna restriction fragments. the major capsid protein (mcp) gene of kvp20 encoding the precursor of major capsid protein (pro- ... | 1998 | 9813227 |
| genetic analysis of bacteriophage-encoded cochaperonins. | early genetic studies identified the escherichia coli groes and groel genes because mutations in them blocked the growth of bacteriophages lambda and t4. subsequent genetic and biochemical analyses have shown that groes and groel constitute a chaperonin machine, absolutely essential for e. coli growth, because it is needed for the correct folding of many of its proteins. in spite of very little sequence identity to groes, the bacteriophage t4-encoded gp31 protein and the bacteriophage rb49-encod ... | 2000 | 11092834 |
| pseudo-t-even bacteriophage rb49 encodes coco, a cochaperonin for groel, which can substitute for escherichia coli's groes and bacteriophage t4's gp31. | bacteriophage t4-encoded gp31 is a functional ortholog of the escherichia coli groes cochaperonin protein. both of these proteins form transient, productive complexes with the groel chaperonin, required for protein folding and other related functions in the cell. however, gp31 is specifically required, in conjunction with groel, for the correct folding of gp23, the major capsid protein of t4. to better understand the interaction between groel and its cochaperonin cognates, we determined whether ... | 2001 | 11104767 |
| identification of important amino acid residues that modulate binding of escherichia coli groel to its various cochaperones. | genetic experiments have shown that the groel/groes chaperone machine of escherichia coli is absolutely essential, not only for bacterial growth but also for the propagation of many bacteriophages including lambda. the virulent bacteriophages t4 and rb49 are independent of the host groes function, because they encode their own cochaperone proteins, gp31 and coco, respectively. e. coli groel44 mutant bacteria do not form colonies above 42 degrees nor do they propagate bacteriophages lambda, t4, o ... | 2001 | 11404317 |
| snapshot of the genome of the pseudo-t-even bacteriophage rb49. | rb49 is a virulent bacteriophage that infects escherichia coli. its virion morphology is indistinguishable from the well-known t-even phage t4, but dna hybridization indicated that it was phylogenetically distant from t4 and thus it was classified as a pseudo-t-even phage. to further characterize rb49, we randomly sequenced small fragments corresponding to about 20% of the approximately 170-kb genome. most of these nucleotide sequences lacked sufficient homology to t4 to be detected in an ncbi b ... | 2002 | 11976309 |
| bacteriophage-encoded cochaperonins can substitute for escherichia coli's essential groes protein. | the escherichia coli chaperonin machine is composed of two members, groel and groes. the groel chaperonin can bind 10-15% of e. coli's unfolded proteins in one of its central cavities and help them fold in cooperation with the groes cochaperonin. both proteins are absolutely essential for bacterial growth. several large, lytic bacteriophages, such as t4 and rb49, use the host-encoded groel in conjunction with their own bacteriophage-encoded cochaperonin for the correct assembly of their major ca ... | 2002 | 12189177 |
| sequence analysis of bacteriophage t4 dna packaging/terminase genes 16 and 17 reveals a common atpase center in the large subunit of viral terminases. | phage dna packaging is believed to be driven by a rotary device coupled to an atpase 'motor'. recent evidence suggests that the phage dna packaging motor is one of the strongest force-generating molecular motors reported to date. however, the atpase center that is responsible for generating this force is unknown. in order to identify the dna translocating atpase, the sequences of the packaging/terminase genes of coliphages t4 and rb49 and vibriophages kvp40 and kvp20 have been analyzed. alignmen ... | 2002 | 12235385 |
| structure and location of gene product 8 in the bacteriophage t4 baseplate. | many bacteriophages, such as t4, t7, rb49, and phi29, have complex, sometimes multilayered, tails that facilitate an almost 100% success rate for the viral particles to infect host cells. in bacteriophage t4, there is a baseplate, which is a multiprotein assembly, at the distal end of the contractile tail. the baseplate communicates to the tail that the phage fibers have attached to the host cell, thereby initiating the infection process. gene product 8 (gp8), whose amino acid sequence consists ... | 2003 | 12729757 |
| [transduction of plasmid antibiotic resistance determinants with pseudo-t-even bacteriophages]. | transduction of antibiotic resistance determinants of the plasmid pbr322 with pseudot-even bacteriophages rb42, rb43, and rb49 was studied. it is established that antibiotic resistance determinants of plasmid pbr322 from escherichia coli reca(+)- and reca(-)-donor strains do not differ significantly in respect to the efficiency of transduction. amber mutants rb43-21, rb43-33, and a double amber mutant rb43am21am33 were obtained. these mutants facilitated transduction experiments in some cases. t ... | 2003 | 12942776 |
| from endonucleases to transcription factors: evolution of the ap2 dna binding domain in plants. | all members of the ap2/erf family of plant transcription regulators contain at least one copy of a dna binding domain called the ap2 domain. the ap2 domain has been considered plant specific. here, we show that homologs are present in the cyanobacterium trichodesmium erythraeum, the ciliate tetrahymena thermophila, and the viruses enterobacteria phage rb49 and bacteriophage felix 01. we demonstrate that the t. erythraeum ap2 domain selectively binds stretches of poly(dg)/poly(dc) showing functio ... | 2004 | 15319480 |
| the sequences and activities of regb endoribonucleases of t4-related bacteriophages. | the regb endoribonuclease encoded by bacteriophage t4 is a unique sequence-specific nuclease that cleaves in the middle of ggag or, in a few cases, ggau tetranucleotides, preferentially those found in the shine-dalgarno regions of early phage mrnas. in this study, we examined the primary structures and functional properties of regb ribonucleases encoded by t4-related bacteriophages. we show that all but one of 36 phages tested harbor the regb gene homologues and the similar signals for transcrip ... | 2004 | 15486207 |
| genetic diversity among five t4-like bacteriophages. | bacteriophages are an important repository of genetic diversity. as one of the major constituents of terrestrial biomass, they exert profound effects on the earth's ecology and microbial evolution by mediating horizontal gene transfer between bacteria and controlling their growth. only limited genomic sequence data are currently available for phages but even this reveals an overwhelming diversity in their gene sequences and genomes. the contribution of the t4-like phages to this overall phage di ... | 2006 | 16716236 |
| plasticity of the gene functions for dna replication in the t4-like phages. | we have completely sequenced and annotated the genomes of several relatives of the bacteriophage t4, including three coliphages (rb43, rb49 and rb69), three aeromonas salmonicida phages (44rr2.8t, 25 and 31) and one aeromonas hydrophila phage (aeh1). in addition, we have partially sequenced and annotated the t4-like genomes of coliphage rb16 (a close relative of rb43), a. salmonicida phage 65, acinetobacter johnsonii phage 133 and vibrio natriegens phage nt-1. each of these phage genomes exhibit ... | 2006 | 16828113 |
| genome analysis of phage js98 defines a fourth major subgroup of t4-like phages in escherichia coli. | numerous t4-like escherichia coli phages were isolated from human stool and environmental wastewater samples in bangladesh and switzerland. the sequences of the major head gene (g23) revealed that these coliphages could be placed into four subgroups, represented by the phages t4, rb69, rb49, and js98. thus, js98 defines a new major subgroup of e. coli t4-like phages. we conducted an analysis of the 169-kb js98 genome sequence. overall, 198 of the 266 js98 open reading frames (orfs) shared amino ... | 2007 | 17693496 |
| t4 phages against escherichia coli diarrhea: potential and problems. | a combination of in vitro and in vivo experiments with comparative phage genomics was used for the rational design of a phage cocktail against e. coli diarrhea. orally applied t4 coliphages representing three different subgroups (t4-, rb49- and js98-like phages) had no negative impact on the murine gut microbiota. t4 phages were found with high titers in the cecum and colon and lower titers in the small intestine, but were not detected in the blood, liver or spleen. no adverse effects were obser ... | 2009 | 19339031 |
| classification of myoviridae bacteriophages using protein sequence similarity. | we advocate unifying classical and genomic classification of bacteriophages by integration of proteomic data and physicochemical parameters. our previous application of this approach to the entirely sequenced members of the podoviridae fully supported the current phage classification of the international committee on taxonomy of viruses (ictv). it appears that horizontal gene transfer generally does not totally obliterate evolutionary relationships between phages. | 2009 | 19857251 |
| mobile regulatory cassettes mediate modular shuffling in t4-type phage genomes. | coliphage phi1, which was isolated for phage therapy in the republic of georgia, is closely related to the t-like myovirus rb49. the approximately 275 open reading frames encoded by each phage have an average level of amino acid identity of 95.8%. rb49 lacks 7 phi1 genes while 10 phi1 genes are missing from rb49. most of these unique genes encode functions without known homologs. many of the insertion, deletion, and replacement events that distinguish the two phages are in the hyperplastic regio ... | 2010 | 20333230 |
| specificity of interactions among the dna-packaging machine components of t4-related bacteriophages. | tailed bacteriophages use powerful molecular motors to package the viral genome into a preformed capsid. packaging at a rate of up to ∼2000 bp/s and generating a power density twice that of an automobile engine, the phage t4 motor is the fastest and most powerful reported to date. central to dna packaging are dynamic interactions among the packaging components, capsid (gp23), portal (gp20), motor (gp17, large "terminase"), and regulator (gp16, small terminase), leading to precise orchestration o ... | 2010 | 21127059 |
| structure of the three n-terminal immunoglobulin domains of the highly immunogenic outer capsid protein from a t4-like bacteriophage. | the head of bacteriophage t4 is decorated with 155 copies of the highly antigenic outer capsid protein or hoc. one hoc molecule binds near the center of each hexameric capsomer. hoc is dispensable for capsid assembly and has been used to display pathogenic antigens on the t4 surface. here we report the crystal structure of a protein containing the first three of four domains of hoc from the bacteriophage rb49, a close relative of t4. the structure shows an approximately linear arrangement of the ... | 2011 | 21632759 |