| amber suppressor mutations in pseudomonas acidovorans. | almost 50% of the clones of pseudomonas acidovorans(plm2) selected for resistance to tetracycline supported the growth of an amber mutant of bacteriophage prd1. | 1979 | 370094 |
| a natural mutant of plasmid rp4 that confers phage resistance and reduced conjugative transfer. | a natural isolate of rp4 (prc#116) acquired from the stanford university plasmid reference center differed from the wild-type incompatibility group p plasmid in several respects. cells of escherichia coli harboring prc#116 were resistant to the incp pili-specific bacteriophage prd1 and gu5, and transferred this plasmid at a lower efficiency than the wild-type rp4. phage sensitivity was restored, and transfer considerably improved in prc#116+ bacteria transformed with plasmid constructs containin ... | 1992 | 1587464 |
| [transfer of bacteriophage prd1 genes into modified plasmid sa of escherichia coli and francisella tularensis cells]. | the donor specific bacteriophage prdi has been shown to mediate the genes transfer into escherichia coli and francisella tularensis cell under certain conditions. it is necessary for the process that the recipient cells inherit the plasmids determining absorbtion of bacteriophages on the cellular surface while the transferred genes are able to be expressed. the frequencies of the tet-gene transfer from the plasmid pskft5 into escherichia coli and francisella tularensis 15 cells inheriting the pl ... | 1991 | 1745272 |
| initiation of bacteriophage prd1 dna replication on single-stranded templates. | in vitro studies have demonstrated that single-stranded dna molecules containing the 3' terminal nucleotides of the prd1 dna replication origin can support initiation by a protein-primed mechanism. we have determined the minimal requirements for priming by analyzing the template activity of various deletion derivatives. our results showed that the 3'-terminal 15 nucleotides of the replication origin are sufficient for priming. the finding that the requirements for recognition of replication orig ... | 1991 | 1960715 |
| large-scale purification of membrane-containing bacteriophage prd1 and its subviral particles. | prd1 is a dsdna virus that infects escherichia coli and salmonella typhimurium. the genome is a linear molecule with 5' covalently linked terminal protein. the virus has a lipid membrane inside the protein coat. we describe the large-scale purification of the virus using a zonal rotor and the yields and quality of the virus and its subviral assemblies for subsequent biophysical measurements. | 1991 | 1994582 |
| nucleotide sequence and transcription of the right early region of bacteriophage prd1. | we have sequenced the rightmost 1,700 base pairs of bacteriophage prd1. this region encompasses the right early region and completes the sequence of all prd1 early functions. we have also mapped the 5' initiation site of right early transcripts in vivo and in vitro. this has allowed us to assign gene xii to an open reading frame and suggests that another open reading frame may also be expressed. gene xii, which has been implicated in the replication process and the regulation of gene expression, ... | 1990 | 2180910 |
| capsomer proteins of bacteriophage prd1, a bacterial virus with a membrane. | bacteriophage prd1 infecting escherichia coli and salmonella typhimurium translocates its membrane from the host plasma membrane to the virus particle. one obligatory component in this process is the major capsid protein. in this investigation we describe characteristics of the homomultimeric major and minor capsid proteins including the sequences of the corresponding genes. the minor capsid protein was found to contain a short collagen-like region (gly-x-y)6. this is the first time this motif h ... | 1990 | 2196741 |
| an essential arginine residue for initiation of protein-primed dna replication. | a group of proteins that act as primers for initiation of linear dna replication are called dna-terminal proteins (terminal proteins). we have found a short stretch of conserved amino acid sequence among the terminal proteins from six different sources. the location of this sequence motif is also similar among the different terminal-proteins. to determine the functional role of this terminal-protein domain in dna replication, we have studied the bacteriophage prd1 system. the prd1 terminal prote ... | 1990 | 2236078 |
| protein-primed replication of bacteriophage prd1 genome in vitro. | a cell-free system has been developed from cells of an escherichia coli strain, carrying cloned genes 1 and 8 of bacteriophage prd1, that catalyzes protein-primed dna synthesis. dna synthesis in vitro is entirely dependent upon the addition of prd1 dna-protein complex as template, mg2+, and four deoxyribonucleoside triphosphates. no in vitro dna synthesis was observed when deproteinized prd1 dna was used as template. the origin and direction of prd1 dna replication in vitro was determined by res ... | 1989 | 2499114 |
| comparison of the amino acid sequence of the lytic enzyme from broad-host-range bacteriophage prd1 with sequences of other cell-wall-peptidoglycan lytic enzymes. | the gene for the lytic enzyme of the lipid-containing, broad-host-range bacteriophage prd1 codes for a protein of 149 amino acids (17271 da). the sequence of the protein is unique when compared to other lytic enzymes sequenced. however, three regions of weak similarity with other phage lytic enzymes were observed. the c-terminal region shared seven amino acids in common with phage p22 lysozyme at a site which is conserved in phage-type lysozymes. | 1989 | 2651121 |
| bacteriophage prd1 terminal protein: expression of gene viii in escherichia coli and purification of the functional p8 product. | the gene viii coding for the bacteriophage prd1 terminal protein p8 has been cloned under the control of the lambda pl promoter. the recombinant plasmid thus obtained (push20) was able to complement a mutation in the phage terminal-protein gene viii. high expression of the cloned gene from this plasmid could be obtained by raising the growth temperature from 28 to 42 degrees c. this heat induction resulted in an increased synthesis of a protein of 30 kda, the size expected for the p8 protein. wh ... | 1989 | 2695403 |
| the genome of lipid-containing bacteriophage prd1, which infects gram-negative bacteria, contains long, inverted terminal repeats. | the bacteriophage prd1 is a lipid-bearing phage that infects a wide variety of gram-negative bacteria, including escherichia coli and salmonella typhimurium when they contain the appropriate plasmid. it contains a linear duplex dna molecule that is covalently bound by its 5' ends to a terminal protein. we report here that the prd1 genome contains a 111-base-pair terminal inverted repeat which does not bear homology to that of any known linear duplex dnas with terminal proteins. we further report ... | 1987 | 3543400 |
| primary structure of the dna terminal protein of bacteriophage prd1. | the genome of a lipid-containing phage, prd1, is replicated by a protein-priming mechanism. we have determined the nucleotide sequence of the prd1 gene 8 which specifies the terminal protein, the protein primer for dna synthesis. the coding region is 780 base pairs long and encodes for 259 amino acids (29,326 daltons). the predicted amino acid sequence of the prd1 terminal protein reveals no substantial homology with that of any known terminal protein. however, hydropathy profiles of the prd1, p ... | 1987 | 3684578 |
| isolation of transfer-negative nif-plasmids (pce1) and their integration into the chromosome of escherichia coli with the help of phage mu. | strain jc5466 of escherichia coli k12 harbouring the nitrogen fixation plasmid pce1 was lysogenized with bacteriophage mu cts, followed by partial induction and infection with bacteriophage prd1. this made it possible to obtain transfer-defective derivatives of pce1, carrying mu prophage. these derivatives could be mobilized by using the helper plasmid pme400 and it was possible to segregate the helper plasmid from the donor plasmid in the transconjugants. by incubating the strains 302 and 328 a ... | 1985 | 3897784 |
| use of phenotypic suppression for direct selection of loss of aminoglycoside antibiotic resistance determinants. | a strain of escherichia coli containing a conditional drug dependent arginine auxotrophy was used to select for the loss of plasmid and/or transposon encoded kanamycin (km) or streptomycin (sm) resistance determinants. because these determinants inactivate the corresponding drug thus eliminating drug suppression, loss of the drug-resistance determinants was selected directly by growth on minimal media plates containing sub-lethal dosages of the drug. this method was used to select loss of km or ... | 1984 | 6092869 |
| identification of a protein bound to the termini of bacteriophage prd1 dna. | lipid-containing bacteriophage prd1 has a double-stranded dna genome of about 14,500 nucleotide base pairs. the phage can infect escherichia coli and salmonella typhimurium as well as other gram-negative bacteria harboring an appropriate plasmid. [35s]methionine label is incorporated into the dna band early in infection. the label remains associated with dna through phenol extraction and boiling with sodium dodecyl sulfate. nuclease treatment of the genome released a protein which migrated as an ... | 1983 | 6620455 |
| isolation of nonsense mutants of lipid-containing bacteriophage prd1. | we isolated nonsense mutants of bacteriophage prd1, a lipid-containing polyhedral virus capable of infecting many genera of gram-negative bacteria. these mutants were grouped into 19 classes on the basis of genetic complementation and sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis. prd1 infection led to the synthesis of at least 25 viral proteins, 17 of which were components of mature virions. the synthesis of proteins fell into the following three classes: very early, middle ... | 1982 | 6757459 |
| assembly of bacteriophage prd1: particle formation with wild-type and mutant viruses. | bacteriophage prd1 contains dna, 17 proteins, and lipid. the assembly pathway involves the formation of empty particles that contain lipid and all of the proteins of mature virions, with the possible exception of one. the major and minor capsid proteins, p3 and p5, occur as soluble multimers before they appear in the empty particles. nonsense mutants of prd1 that involve structural proteins of the virion other than p3 form particles that are missing only the defective protein. those mutants that ... | 1982 | 6816950 |
| structure of the lipid-containing bacteriophage prd1: disruption of wild-type and nonsense mutant phage particles with guanidine hydrochloride. | the lipid-containing bacteriophage prd1 was disrupted, and the subviral particles were studied. guanidine treatment released two phage proteins (p3 and p5). these proteins form the polyhedral capsid. the remaining phage proteins were associated with the phage membrane vesicle. the vesicle was capable of forming a tubular structure. the isolated phage membrane vesicles aggregated readily. we found that aggregation and tube formation were associated with specific phage proteins (p11 and p18, respe ... | 1982 | 6816951 |
| bacterial conjugation mediated by plasmid rp4: rsf1010 mobilization, donor-specific phage propagation, and pilus production require the same tra2 core components of a proposed dna transport complex. | dna transfer by bacterial conjugation requires a mating pair formation (mpf) system that specifies functions for establishing the physical contact between the donor and the recipient cell and for dna transport across membranes. plasmid rp4 (incp alpha) contains two transfer regions designated tra1 and tra2, both of which contribute to mpf. twelve components are essential for mpf, traf of tra1 and 11 tra2 proteins, trbb, -c, -d, -e, -f, -g, -h, -i, -j, -k, and -l. the phenotype of defined mutants ... | 1995 | 7642506 |
| family a and family b dna polymerases are structurally related: evolutionary implications. | in order to establish the evolutionary relationship between the family a and b dna polymerases, we have closely compared the 3'-->5' exonuclease domains between the klenow fragment of e.coli dna polymerase i (a family a dna polymerase) and the bacteriophage prd1 dna polymerase, the smallest member of the dna polymerase family b. although the prd1 dna polymerase has a smaller 3'-->5' exonuclease domain, its active sites appear to be very similar to those of the klenow fragment. site-directed muta ... | 1994 | 7816603 |
| functional organization of the bacteriophage prd1 genome. | prd1 is a broad-host-range virus that infects escherichia coli cells. it has a linear double-stranded dna genome that replicates by a protein-primed mechanism. the virus particle is composed of a protein coat enclosing a lipid membrane. on the basis of this structure, prd1 is being used as a membrane biosynthesis and structure model. in this investigation, we constructed the transcription map of the 15-kb-long phage genome. this was achieved by a computer search of putative promoters, which were ... | 1994 | 8188607 |
| protein-primed dna replication: role of inverted terminal repeats in the escherichia coli bacteriophage prd1 life cycle. | escherichia coli bacteriophage prd1 and its relatives contain linear double-stranded dna genomes, the replication of which proceeds via a protein-primed mechanism. characteristically, these molecules contain 5'-covalently bound terminal proteins and inverted terminal nucleotide sequences (inverted terminal repeats [itrs]). the itrs of each prd1 phage species have evolved in parallel, suggesting communication between the molecule ends during the life cycle of these viruses. this process was studi ... | 1993 | 8331725 |
| binding of an escherichia coli double-stranded dna virus prd1 to a receptor coded by an incp-type plasmid. | incp plasmid rp1 tra regions are needed to assemble the receptor for lipid-containing double-stranded dna bacteriophage prd1 on the cell surface. using radioactively labeled phage and electron microscopic techniques, we showed that the surfaces of salmonella typhimurium(rp1) and escherichia coli(rp1) cells contained approximately 50 and 20 prd1 binding sites, respectively. expression of the receptor was growth phase dependent and was highest at late logarithmic or early stationary phase. the prd ... | 1993 | 8387995 |
| characterization of the dna-protein complex at the termini of the bacteriophage prd1 genome. | dna of bacteriophage prd1 has protein p8 at its termini. extracts of infected cells are able to derivatize p8 in vitro with labeled dgtp. two early proteins, p1 and p8, products of genes i and viii, respectively, are the only phage proteins necessary for the formation of the protein p8-dgmp complex. this was shown by complementation of extracts from cells infected with mutants and by use of extracts from cells carrying cloned genes i and viii. with escherichia coli mutants that are temperature s ... | 1984 | 6368864 |
| dissociation of the lipid-containing bacteriophage prd1: effects of heat, ph, and sodium dodecyl sulfate. | the double-stranded dna bacteriophage prd1 replicates in escherichia coli and salmonella typhimurium. it has an outer protein coat surrounding a membrane. the phage lipids are derived from the host, but the membrane proteins are of phage origin. in this investigation we studied the effects of heat, ph, and sodium dodecyl sulfate on the integrity of phage particles. heat and high ph result in the release of the main coat protein, p3, as trimers, whereas treatment of phage particles with detergent ... | 1993 | 8503173 |
| isolation of a phospholipid-free protein shell of bacteriophage prd1, an escherichia coli virus with an internal membrane. | prd1 is a double-stranded dna virus infecting escherichia coli and salmonella typhimurium. it has an icosahedral outer protein capsid which encloses the viral membrane, inside of which resides the phage genome. in this investigation we demonstrate the detergent resistance of the intact virus particles. the membrane of empty dna-free particles, however, is very sensitive to detergent action. we assume that their sensitivity is due to the access of detergents through a portal structure to the viru ... | 1993 | 8503174 |
| establishment of a physical and genetic map for bacteriophage prd1. | dna was isolated from the lipid-containing bacteriophage prd1 and subjected to restriction endonuclease analysis. the total genome size is 14.7 kb. prd1 dna was resistant to cutting by fifteen restriction endonucleases with six base specificity. haeii made thirty-seven cuts in the dna, mboi made one cut, and mnli made six cuts. dna that was not treated with protease yielded two fewer fragments when treated with haeii. evidence is presented to indicate that the prd1 dna has protein at the ends of ... | 1983 | 6308389 |
| dna packaging orders the membrane of bacteriophage prd1. | bacteriophage prd1 contains a linear dsdna genome enclosed by a lipid membrane lying within a protein coat. determination of the structure of the detergent-treated particle to 2 nm by cryo-electron microscopy and three-dimensional reconstruction has defined the position of the major coat protein p3. the coat contains 240 copies of trimeric p3 packed into positions of local 6-fold symmetry on a t = 25 lattice. the three-dimensional structures of the prd1 virion and a dna packaging mutant to a res ... | 1995 | 8557027 |
| structure, interactions and dynamics of prd1 virus i. coupling of subunit folding and capsid assembly. | bacteriophage prd1, which infects escherichia coli and salmonella typhimurium, consists of an icosahedral capsid enclosing a membrane-packaged double-stranded dna genome. the viral shell has been investigated using time and temperature resolved raman and ultraviolet-resonance raman spectroscopy to reveal novel features of the capsid structure and its pathway of assembly from p3 subunits. raman spectra show that the shell is thermostable to 50 degrees c, and disassembles between 50 and 70 c degre ... | 1996 | 8632462 |
| molecular cloning of bacteriophage prd1 genomic fragments. | dna from bacteriophage prd1 was extracted and partially digested with restriction endonuclease haeii. the digest was cloned into the psti site of plasmid pbr322 by homopolymer tailing with guanidylate tails on the plasmid and cytidylate tails on the phage dna. insert bearing plasmids were isolated by transforming e. coli strains for tetracycline resistance and screening for ampicillin sensitivity. these strains were then screened for the ability to accomplish marker rescue of nonsense mutants of ... | 1983 | 6308388 |
| bacteriophage prd1 dna polymerase: evolution of dna polymerases. | a small lipid-containing bacteriophage prd1 specifies its own dna polymerase that utilizes terminal protein as a primer for dna synthesis. the prd1 dna polymerase gene has been sequenced, and its amino acid sequence has been deduced. this protein-primed dna polymerase consists of 553 amino acid residues with a calculated molecular weight of 63,300. thus, it appears to be the smallest dna polymerase ever isolated from prokaryotic cells. comparison of the prd1 dna polymerase sequence with other dn ... | 1987 | 3479792 |
| the complete nucleotide sequence of the left very early region of escherichia coli bacteriophage prd1 coding for the terminal protein and the dna polymerase. | dna molecules replicating in a linear form have been found in certain viruses and plasmids of both prokaryotic and eukaryotic origin. characteristic of this type of molecules are the proteins covalently linked to their 5' ends and inverted terminal nucleotide sequences. the molecules replicate via a protein-priming mechanism, where participants include terminal protein and a specific polymerase. we report here the nucleotide sequence of the left very early region of escherichia coli bacteriophag ... | 1987 | 3322943 |
| assembly of a functional phage prd1 receptor depends on 11 genes of the incp plasmid mating pair formation complex. | prd1, a lipid-containing double-stranded dna bacteriophage, uses the mating pair formation (mpf) complex encoded by conjugative incp plasmids as a receptor. functions responsible for conjugative transfer of incp plasmids are encoded by two distinct regions, tra1 and tra2. ten tra2 region gene products (trbb to trbl) and one from the tra1 region (traf) form the mpf complex. we carried out a mutational analysis of the prd1 receptor complex proteins by isolating spontaneous prd1-resistant mutants. ... | 1997 | 9244259 |
| changes in host cell energetics in response to bacteriophage prd1 dna entry. | double-stranded dna bacteriophage prd1 infects a variety of gram-negative bacteria harboring an incp-type conjugative plasmid. the plasmid codes for the dna transfer phage receptor complex in the cell envelope. our goal was, by using a collection of mutant phage particles for which the variables are the dna content and/or the presence of the receptor-binding protein, to obtain information on the energy requirements for dna entry as well as on alterations in the cellular energetics taking place d ... | 1997 | 9260965 |
| a specific protease encoded by the conjugative dna transfer systems of incp and ti plasmids is essential for pilus synthesis. | traf, an essential component of the conjugative transfer apparatus of the broad-host-range plasmid rp4 (incp), which is located at the periplasmic side of the cytoplasmic membrane, encodes a specific protease. the traf gene products of incp and ti plasmids show extensive similarities to prokaryotic and eukaryotic signal peptidases. mutational analysis of rp4 traf revealed that the mechanism of the proteolytic cleavage reaction resembles that of signal and lexa-like peptidases. among the rp4 tran ... | 1997 | 9294428 |
| genetic and physical characterization of trimethoprim resistance plasmids from shigella sonnei and shigella flexneri. | analysis of six shigella flexneri and four s. sonnei isolates with trimethoprim (tp) resistance from clinical cases in ontario has shown that, in all isolates, the tp resistance is mediated by gene(s) on conjugative, multiple antibiotic-resistance plasmids. the physical and genetic characterization of these plasmids revealed that there are three different tp resistance plasmids. one group, composed of all six s. flexneri plasmids, consists of plasmids which are about 70 megadaltons (mda) and inh ... | 1987 | 2825949 |
| the organization of the right-end early region of bacteriophage prd1 genome. | bacteriophage prd1 is the only protein-primed dna replication system known to operate in escherichia coli. the left-genome end of prd1 contains the early genes for the terminal protein and the dna polymerase. these genes have been sequenced and the proteins have been produced separately. in this investigation we completed the analysis of the prd1 early dna regions by cloning and sequencing the right end genome containing early genes xii and xix. we compared the structure of the right- and left-t ... | 1989 | 2695404 |
| analysis of the multimeric state of proteins by matrix assisted laser desorption/ionization mass spectrometry after cross-linking with glutaraldehyde. | we have undertaken a systematic study on the suitability of matrix-assisted laser desorption/ionization mass spectrometry to analyze and determine the multimericity of several proteins after cross-linking with glutaraldehyde. using both commercially available proteins and others of viral origin currently being characterized in our laboratory, we studied the range of concentrations of cross-linker and protein for optimal analysis. under the conditions developed during this study, we confirmed the ... | 1999 | 10048230 |
| purification and characterization of the assembly factor p17 of the lipid-containing bacteriophage prd1. | assembly factors, proteins assisting the formation of viral structures, have been found in many viral systems. the gene encoding the assembly factor p17 of bacteriophage prd1 has been cloned and expressed in escherichia coli. p17 acts late in phage assembly, after capsid protein folding and multimerization, and sorting of membrane proteins has occurred. p17 has been purified to near homogeneity. it is a tetrameric protein displaying a rather high heat stability. the protein is largely in an alph ... | 1999 | 10095794 |
| [the use of the plasmid pth10 for isolating the donor strains of pseudomonas mallei]. | the plasmid pth10 was transfered by conjugation into the pseudomonas mallei strains. an attempt to construct the donor strains using the widely known technique employing the homology between the plasmid and chromosome due to the transposon tn1 carried by the plasmid was unsuccessful. among the clones resistant to bacteriophage prd1 the variants were selected with the supposed integration of the plasmid into the chromosome. the latter clones required the ability to transfer the auxotrophic chromo ... | 1989 | 2664486 |
| structural study of the lipid-containing bacteriophage prd1 and its capsid and dna components by laser raman spectroscopy. | the raman spectrum of a virus contains the structural signature of each of its molecular components (thomas, 1987). we report the first raman spectrum obtained from an intact, lipid-containing virus--the icosahedral bacteriophage prd1--and show that this spectrum contains characteristic structure markers for the major capsid protein, the packaged double-stranded dna genome, and the viral membrane which resides between the capsid and dna. we find that the packaged genome of prd1 exhibits raman ma ... | 1990 | 2383568 |
| characterization of a dna binding protein of bacteriophage prd1 involved in dna replication. | escherichia coli phage prd1 protein p12, involved in prd1 dna replication in vivo, has been highly purified from e. coli cells harbouring a gene xii-containing plasmid. protein p12 binds to single-stranded dna as shown by gel retardation assays and nuclease protection experiments. binding of protein p12 to single-stranded dna increases about 14% the contour length of the dna as revealed by electron microscopy. binding to single-stranded dna seems to be cooperative, and it is not sequence specifi ... | 1990 | 2251117 |
| structure and assembly of bacteriophage prd1, and escherichia coli virus with a membrane. | this article describes the structure and assembly of bacteriophage prd1, a lipid-containing virus able to infect escherichia coli. this phage, with an approximate diameter of 65 nm, is composed of an outer protein shell surrounding a lipid-protein membrane which, in turn, encloses the nucleic acid. the phage genome consists of a single linear dsdna molecule of about 15 kb that has a protein covalently linked to each of its 5' ends. this protein is used as a primer in dna replication. during asse ... | 1990 | 2088450 |
| 'déjà vu all over again': the similar structures of bacteriophage prd1 and adenovirus. | | 2000 | 10707053 |
| sequence requirements for protein-primed dna replication of bacteriophage prd1. | in vitro studies have demonstrated that linear duplex, protein-free dna molecules containing an inverted terminal repeat (itr) sequence of the prd1 genome at one end can undergo replication by a protein-primed mechanism. no dna replication was observed when the itr sequence was deleted or was not exposed at the terminus of the template dna. we have determined the minimal origin of replication by analyzing the template activity of various deletion derivatives. our results showed that the terminal ... | 1991 | 2023249 |
| a new mutant class, made by targeted mutagenesis, of phage prd1 reveals that protein p5 connects the receptor binding protein to the vertex. | phage prd1 and adenovirus share a number of structural and functional similarities, one of which is the vertex organization at the fivefold-symmetry positions. we developed an in vitro mutagenesis system for the linear prd1 genome in order to make targeted mutations. the role of protein p5 in the vertex structure was examined by this method. mutation in gene v revealed that protein p5 is essential. the absence of p5 did not compromise the particle assembly or dna packaging but led to a deficient ... | 2000 | 10933684 |
| high-frequency transfer of linear dna containing 5'-covalently linked terminal proteins: electroporation of bacteriophage prd1 genome into escherichia coli. | using electroporation with the phage prd1 genome, we set up a high-frequency dna transfer system for a linear dsdna molecule with 5'-covalently linked terminal proteins. the transfer was saturated when more than 100 ng of prd1 genome was used. electroporation efficiency was about four orders of magnitude higher than that obtained with transfection. removal of the terminal protein abolished plaque formation, which could not be rescued by supplying the terminal protein or phage dna polymerase or b ... | 1991 | 1886619 |
| genome organization of membrane-containing bacteriophage prd1. | we have determined the nucleotide sequence of the late region (11 kbp) of the lipid-containing bacteriophage prd1. gene localization was carried out by complementing nonsense phage mutants with genomic clones containing specific reading frames. the localization was confirmed by sequencing the n-termini of isolated gene products as well as sequencing the n-termini of tryptic fragments of the phage membrane-associated proteins. this, with the previously obtained sequence of the early regions, allo ... | 1991 | 1853567 |
| overexpression, purification, and characterization of escherichia coli bacteriophage prd1 dna polymerase. in vitro synthesis of full-length prd1 dna with purified proteins. | the bacteriophage prd1 dna polymerase gene (gene i) has been cloned into the expression vector pplh101 under the control of the lambda pl promoter. tailoring of an efficient ribosome binding site in front of the gene by polymerase chain reaction led to a high level heat-inducible expression of the corresponding gene product (p1) in escherichia coli cells. expression was confirmed in vivo by complementation of phage prd1 dna polymerase gene mutants and in vitro by formation of the genome terminal ... | 1991 | 1655759 |
| in vitro replication of bacteriophage prd1 dna. metal activation of protein-primed initiation and dna elongation. | bacteriophage prd1 replicates its dna by means of a protein-primed replication mechanism. compared to mg2+, the use of mn2+ as the metal activator of the phage dna polymerase results in a great stimulation of the initiation reaction. the molecular basis of the observed stimulatory effect is an increase in the velocity of the reaction. the phage dna polymerase is also able to catalyze the formation of the initiation complex in the absence of dna template. although the presence of mn2+ does not af ... | 1992 | 1324473 |
| combined em/x-ray imaging yields a quasi-atomic model of the adenovirus-related bacteriophage prd1 and shows key capsid and membrane interactions. | the dsdna bacteriophage prd1 has a membrane inside its icosahedral capsid. while its large size (66 mda) hinders the study of the complete virion at atomic resolution, a 1.65-a crystallographic structure of its major coat protein, p3, is available. cryo-electron microscopy (cryo-em) and three-dimensional reconstruction have shown the capsid at 20-28 a resolution. striking architectural similarities between prd1 and the mammalian adenovirus indicate a common ancestor. | 2001 | 11591347 |
| a minor capsid protein p30 is essential for bacteriophage prd1 capsid assembly. | bacteriophage prd1 is a double-stranded dna virus infecting gram-negative hosts. it has a membrane component located in the interior of the isometric capsid. in addition to the major capsid protein p3, the capsid contains a 9 kda protein p30. protein p30 is proposed to be located between the adjacent facets of the icosahedral capsid and is required for stable capsid assembly. in its absence, an empty phage-specific membrane vesicle is formed. the major protein component of this vesicle is a phag ... | 2001 | 11697904 |
| rp1 properties and fertility inhibition among p, n, w, and x incompatibility group plasmids. | incompatibility group p plasmids demonstrate strong entry exclusion properties. stringent incompatibility is also observed in the absence of entry exclusion. these observations have been facilitated by the study of a nontransmissible plasmid, rp1-s2, derived from rp1 by transductional shortening. rp1-s2 retains carbenicillin and tetracycline resistances as well as loci that cause either the loss of p plasmids (incp) or a locus specifying susceptibility to curing (sinp) in the presence of a p pla ... | 1975 | 1095558 |
| overproduction, purification, and characterization of dna-binding protein p19 of bacteriophage prd1. | the early protein, p19, of bacteriophage prd1 was purified after overexpression of the cloned gene, xix, in escherichia coli dh5 alpha cells. the purified protein binds as multimers to single-stranded dna (ssdna), and with a lower affinity to double-stranded dna (dsdna), without sequence-specificity. two distinct p19-ssdna complexes were discovered in gel- mobility-shift assays at different protein:dna ratios. p19 was capable of fully protecting ssdna against nuclease p1. electron microscopy of ... | 1993 | 8472964 |
| in vitro replication of bacteriophage prd1 dna. characterization of the protein-primed initiation site. | bacteriophage prd1 replicates its dna by means of a protein-primed replication mechanism. using single-stranded oligonucleotide templates carrying the sequence corresponding to the 25 first bases of the 3' end of prd1 dna, and mg2+ as the activating metal ion of the phage dna polymerase, we show that the fourth base from the 3' end of the template directs, by base complementarity, the dnmp to be linked to the phage terminal protein (tp) in the initiation reaction. this result suggests that phage ... | 1993 | 8367287 |
| the small viral membrane-associated protein p32 is involved in bacteriophage prd1 dna entry. | the lipid-containing bacteriophage prd1 infects a variety of gram-negative cells by injecting its linear double-stranded dna genome into the host cell cytoplasm, while the protein capsid is left outside. the virus membrane and several structural proteins are involved in phage dna entry. in this work we identified a new infectivity protein of prd1. disruption of gene xxxii resulted in a mutant phenotype defective in phage reproduction. the absence of the protein p32 did not compromise the particl ... | 2002 | 11967303 |
| field and laboratory investigations of inactivation of viruses (prd1 and ms2) attached to iron oxide-coated quartz sand. | field and laboratory experiments were conducted to investigate inactivation of viruses attached to mineral surfaces. in a natural gradient transport field experiment, bacteriophage prd1, radiolabeled with 32p, was injected into a ferric oxyhydroxide-coated sand aquifer with bromide and linear alkylbenzene sulfonates. in a zone of the aquifer contaminated by secondary sewage infiltration, small fractions of infective and 32p-labeled prd1 broke through with the bromide tracer,followed bythe slow r ... | 2002 | 12075796 |
| bacteriophage pm2 has a protein capsid surrounding a spherical proteinaceous lipid core. | the marine double-stranded dna (dsdna) bacteriophage pm2, studied since 1968, is the type organism of the family corticoviridae, infecting two gram-negative pseudoalteromonas species. the virion contains a membrane underneath an icosahedral protein capsid composed of two structural proteins. the purified major capsid protein, p2, appears as a trimer, and the receptor binding protein, p1, appears as a monomer. the c-terminal part of p1 is distal and is responsible for receptor binding activity. t ... | 2002 | 12134022 |
| purification of viruses and macromolecular assemblies for structural investigations using a novel ion exchange method. | we describe a novel ion exchange chromatographic technique suitable for large-scale preparation of viruses and other biomacromolecular assemblies in highly purified form. the method, which utilizes anion exchange on either of two commercially available cellulose cartridges, is applied to the escherichia coli bacteriophage prd1. viral particles eluted from both qma and deae cartridges retain infectivity and exhibit greater homogeneity of composition, as judged by gel electrophoresis and electron ... | 1994 | 8178473 |
| gene xv of bacteriophage prd1 encodes a lytic enzyme with muramidase activity. | bacteriophage prd1 is a lipid-containing virus that infects a variety of gram-negative bacteria, including escherichia coli. the phage lyses its host by virtue of a virally-encoded lytic enzyme, the synthesis of which has been assigned to gene xv on the basis of complementation analysis and experiments with mutant phages. we report here the cloning of gene xv into an expression plasmid and the purification of its product, protein p15, to near homogeneity. the purified protein p15, identified by ... | 1994 | 7925454 |
| purification and characterization of prd1 dna polymerase. | a small lipid-containing bacteriophage prd1 encodes a dna polymerase that utilizes a protein primer for the initiation of dna replication. the purification of the prd1 dna polymerase has been hampered by the insolubility of the overexpressed enzyme in escherichia coli cells. we have developed a simple and rapid procedure for purification of the overexpressed prd1 dna polymerase. this method is based on guanidine hydrochloride denaturation and renaturation of the insoluble prd1 dna polymerase ove ... | 1994 | 7918621 |
| bacteriophage prd1: a broad host range dsdna tectivirus with an internal membrane. | | 1995 | 7793328 |
| expression in escherichia coli of rat neurotensin receptor fused to membrane proteins from the membrane-containing bacteriophage prd1. | bacteriophage prd1 is a membrane-containing phage which could be used for expression of foreign membrane proteins such as neurotensin receptor (ntr), a seven-helix g-protein coupled receptor. to ensure recognition of ntr by the phage system six different fusion genes were constructed, each encoding a different phage integral membrane protein fused to the n-terminus of ntr, and expression of the fusion proteins in escherichia coli was analysed. here we report the identification of two fusion cons ... | 1994 | 7710700 |
| crystallization of the membrane-containing bacteriophage prd1 in quartz capillaries by vapour diffusion. | crystals of bacteriophage prd1, a virus containing an internal lipid bilayer, have been grown in thin-walled quartz capillary tubes by vapour diffusion as a means of eliminating mechanical handling of the crystals during data collection. it has been found that the addition of polyethylene glycol 20 000 (peg 20k) to the mother liquor that bathes the crystals allows far higher resolution diffraction intensities to be observed. growing and treating the crystals in this way has produced a small numb ... | 2003 | 12595719 |
| topology of the major capsid protein p3 of bacteriophage prd1: analysis using monoclonal antibodies and c-terminally truncated proteins. | trimeric capsomeres of protein p3 (395 aa) are the main component of the phage prd1 capsid, which encloses a lipid-protein vesicle containing the viral dsdna genome. in this study we characterize a panel of monoclonal antibodies (mab) against p3. the epitopes recognized by the mabs are analyzed by immunoprecipitation of intact virions or of released p3 trimers, and by western blotting using a series of c-terminally truncated p3 molecules. nine of the mabs recognize epitopes on the virion surface ... | 1993 | 7504366 |
| bacteriophage prd1 proteins: cross-linking and scanning transmission electron microscopy analysis. | bacteriophage prd1, a double-stranded dna virus infecting escherichia coli, has a membrane inside the protein capsid. chemical cross-linking and scanning transmission electron microscopy showed that the multimeric major coat protein (p3) exists in a trimeric form. cross-linking revealed, in addition, that protein p11, located between the protein coat and the membrane, exists also as a homotrimer. minor protein p7 was associated with the major coat protein p3. under nonreducing conditions the inf ... | 1993 | 8503175 |
| the unique vertex of bacterial virus prd1 is connected to the viral internal membrane. | icosahedral double-stranded dna (dsdna) bacterial viruses are known to package their genomes into preformed procapsids via a unique portal vertex. bacteriophage prd1 differs from the more commonly known icosahedral dsdna phages in that it contains an internal lipid membrane. the packaging of prd1 is known to proceed via preformed empty capsids. now, a unique vertex has been shown to exist in prd1. we show in this study that this unique vertex extends to the virus internal membrane via two integr ... | 2003 | 12743288 |
| a novel plasmid gene involved in bacteriophage prd1 infection and conjugative host-range. | prd1 infects bacteria carrying incn plasmids by binding to their conjugative pili. mutations in a plasmid locus kika close to the pilus region result in prd1 resistance and reduced conjugation proficiency to klebsiella but not to escherichia coli. one of the two genes of kika is sufficient to restore both normal phenotypes. prd1 binds to cells carrying the mutant plasmid but fails to inject its genome. | 1996 | 8812786 |
| identification and mutational analysis of bacteriophage prd1 holin protein p35. | holin proteins are phage-induced integral membrane proteins which regulate the access of lytic enzymes to host cell peptidoglycan at the time of release of progeny viruses by host cell lysis. we describe the identification of the membrane-containing phage prd1 holin gene (gene xxxv). the prd1 holin protein (p35, 12.8 kda) acts similarly to its functional counterpart from phage lambda (gene s), and the defect in prd1 gene xxxv can be corrected by the presence of gene s of lambda. several nonsense ... | 2003 | 12813073 |
| probing phage prd1-specific proteins with monoclonal and polyclonal antibodies. | four new specificity class mabs against prd1 proteins (p6, p7/14, p11, p18) and polyclonal antiserum against the minor capsid protein p5 were produced. the antibodies were used to analyze the phage protein distribution inside the host cell during infection as well as in the virion. the minor component of the capsid, p5, was shown to be located on the surface of the virion. the proteins responsible for particle infectivity were localized to the membrane fraction of the host cells. in addition, by ... | 1997 | 9007073 |
| assembly of membrane-containing bacteriophage prd1 is dependent on groel and groes. | assembly of the broad-host-range bacteriophage prd1 involves translocation of the virus-specific membrane to the inside of the icosahedral protein shell formed of trimeric coat proteins. the formation of prd1 particles is, in addition to the virus-encoded assembly factors p10 and p17, dependent on groel/groes chaperonins. the chaperonins assist in the folding of the capsid proteins p3 and p5 and in the assembly of viral membrane proteins. | 1997 | 9007074 |
| trwd, a protein encoded by the incw plasmid r388, displays an atp hydrolase activity essential for bacterial conjugation. | a 1.7-kilobase pair segment from the conjugative transfer region of plasmid r388 dna was cloned and sequenced. it contained trwd, a gene essential for plasmid r388 conjugation, for expression of the conjugative w-pilus and for sensitivity to phage prd1. the deduced amino acid sequence of trwd showed homology to the pule/virb11 superfamily of potential atpases involved in various types of transport processes. a fusion of trwd with the glutathione s-transferase (gst) was constructed, and the resul ... | 1997 | 9325277 |
| molecular phylogeny of phi29-like phages and their evolutionary relatedness to other protein-primed replicating phages and other phages hosted by gram-positive bacteria. | the phi29-like phage genus of podoviridae family contains phages b103, bs32, ga-1, m2, nf, phi15, phi29, and pza that all infect bacillus subtilis. they have very similar morphology and their genomes consist of linear double-stranded dna of approximately 20 kb. the nucleotide sequences of individual genomes or their parts determined thus far show that these phages evolved from a common ancestor. a terminal protein (tp) that is covalently bound to the dna 5'-end primes dna replication of these ph ... | 1999 | 9929388 |
| characterization of coliphage pr772 and evaluation of its use for virus filter performance testing. | virus filtration is a key clearance unit operation in the manufacture of recombinant protein, monoclonal antibody, and plasma-derived biopharmaceuticals. recently, a consensus has developed among filter manufacturers and end users about the desirability of a common nomenclature and a standardized test for classifying and identifying virus-retentive filters. the parenteral drug association virus filter task force has chosen pr772 as the model bacteriophage to standardize nomenclature for large-po ... | 2004 | 15294825 |
| integral membrane protein p16 of bacteriophage prd1 stabilizes the adsorption vertex structure. | the icosahedral membrane-containing double-stranded dna bacteriophage prd1 has a labile receptor binding spike complex at the vertices. this complex, which is analogous to that of adenovirus, is formed of the penton protein p31, the spike protein p5, and the receptor binding protein p2. upon infection, the internal phage membrane transforms into a tubular structure that protrudes through a vertex and penetrates the cell envelope for dna injection. we describe here a new class of prd1 mutants lac ... | 2004 | 15331712 |
| a data mining approach for analyzing density maps representing macromolecular structures. | results of electron microscopy-based three-dimensional reconstructions of macromolecules or their complexes are usually stored as density maps. each point ("voxel") in the map represents a density value and one approach for studying details of the map is to display an isosurface enclosing areas of interest. we have taken a data mining approach not only focusing on the areas of immediate interest but determining all possible separate entities ("blobs") from a density map. after the entire density ... | 1999 | 10222277 |
| bacteriophage prd1 contains a labile receptor-binding structure at each vertex. | bacteriophage prd1 is a membrane-containing virus with an unexpected similarity to adenovirus. we mutagenized unassigned prd1 genes to identify minor capsid proteins that could be structural or functional analogs to adenovirus proteins. we report here the identification of an amber mutant, sus525, in an essential prd1 gene xxxi. the gene was cloned and the gene product was overexpressed and purified to near homogeneity. analytical ultracentrifugation and gel filtration showed that p31 is a homop ... | 1999 | 10448038 |
| does common architecture reveal a viral lineage spanning all three domains of life? | our discovery that the major coat protein of bacteriophage prd1 resembles that of human adenovirus raised the unexpected possibility that viruses infecting bacteria could be related by evolution to those infecting animal hosts. we first review the development of this idea. we then describe how we have used structure-based modeling to show that several other viruses with no detectable sequence similarity are likely to have coats constructed from similar proteins-the "double-barrel trimer." there ... | 2004 | 15574324 |
| a field study of virus removal in septic tank drainfields. | two field studies were conducted at a research station in tampa, florida to assess the removal of bacteriophage prd1 from wastewater in septic tank drainfields. infiltration cells were seeded with prd1 and bromide and the effects of effluent hydraulic loading rate and rainfall on virus removal were monitored. septic tank effluent samples were collected after passage through 0.6 m of unsaturated fine sand and prd1 was detected over an average of 67 d. bacteriophage prd1 breakthrough was detected ... | 2001 | 11789999 |
| minor proteins, mobile arms and membrane-capsid interactions in the bacteriophage prd1 capsid. | bacteriophage prd1 shares many structural and functional similarities with adenovirus. a major difference is the prd1 internal membrane, which acts in concert with vertex proteins to translocate the phage genome into the host. multiresolution models of the prd1 capsid, together with genetic analyses, provide fine details of the molecular interactions associated with particle stability and membrane dynamics. the n- and c-termini of the major coat protein (p3), which are required for capsid assemb ... | 2002 | 12219080 |
| diffraction quality crystals of prd1, a 66-mda dsdna virus with an internal membrane. | it has proved difficult to obtain well diffracting single crystals of macromolecular complexes rich in lipid. we report here the path that has led to crystals of the bacteriophage prd1, a particle containing approximately 2,000 protein subunits from 18 different protein species, around 10 of which are integral membrane proteins associated with a host-derived lipid bilayer of some 12,500 lipid molecules. these crystals are capable of diffracting x-rays to bragg spacings below 4a. it is hoped that ... | 2002 | 12406692 |
| the structure and evolution of the major capsid protein of a large, lipid-containing dna virus. | paramecium bursaria chlorella virus type 1 (pbcv-1) is a very large, icosahedral virus containing an internal membrane enclosed within a glycoprotein coat consisting of pseudohexagonal arrays of trimeric capsomers. each capsomer is composed of three molecules of the major capsid protein, vp54, the 2.0-a resolution structure of which is reported here. four n-linked and two o-linked glycosylation sites were identified. the n-linked sites are associated with nonstandard amino acid motifs as a resul ... | 2002 | 12411581 |
| the holin protein of bacteriophage prd1 forms a pore for small-molecule and endolysin translocation. | prd1 is a bacteriophage with an icosahedral outer protein layer surrounding the viral membrane, which encloses the linear double-stranded dna genome. prd1 infects gram-negative cells harboring a conjugative incp plasmid. here we studied the lytic functions of prd1. using infected cells and plasmid-borne lysis genes, we demonstrated that a two-component lysis system (holin-endolysin) operates to release progeny phage particles from the host cell. monitoring of ion fluxes and the atp content of th ... | 2005 | 16030234 |
| sequential model of phage prd1 dna delivery: active involvement of the viral membrane. | dna translocation across the barriers of recipient cells is not well understood. viral dna delivery mechanisms offer an opportunity to obtain useful information in systems in which the process can be arrested to a number of stages. prd1 is an icosahedral double-stranded (ds)dna bacterial virus with an internal membrane. it is an atypical dsdna phage, as any of the vertex spikes can be used for receptor recognition. in this report, we dissect the prd1 dna entry into a number of steps: (i) outer m ... | 2002 | 12453208 |
| membrane proteins modulate the bilayer curvature in the bacterial virus bam35. | biological membranes control the flow of molecules into and out of cells, and they transmit information about the milieu. structural studies of membrane-containing viruses provide one way to study these membranes in situ. cryo-electron microscopy and image reconstruction of bacteriophage bam35 to 7.3 a resolution revealed a membrane bilayer constrained within an icosahedrally symmetric pseudo t = 25 capsid. a total of 60 large transmembrane protein complexes affect the curvature and thickness of ... | 2005 | 16338410 |
| a direct transposon insertion tool for modification and functional analysis of viral genomes. | advances in dna transposition technology have recently generated efficient tools for various types of functional genetic analyses. we demonstrate here the power of the bacteriophage mu-derived in vitro dna transposition system for modification and functional characterization of a complete bacterial virus genome. the linear double-stranded dna genome of escherichia coli bacteriophage prd1 was studied by insertion mutagenesis with reporter mini-mu transposons that were integrated in vitro into iso ... | 2003 | 12477817 |
| preliminary crystallographic analysis of the major capsid protein p2 of the lipid-containing bacteriophage pm2. | pm2 (corticoviridae) is a dsdna bacteriophage which contains a lipid membrane beneath its icosahedral capsid. in this respect it resembles bacteriophage prd1 (tectiviridae), although it is not known whether the similarity extends to the detailed molecular architecture of the virus, for instance the fold of the major coat protein p2. structural analysis of pm2 has been initiated and virus-derived p2 has been crystallized by sitting-nanodrop vapour diffusion. crystals of p2 have been obtained in s ... | 2005 | 16511151 |
| viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, florida. | domestic wastewater disposal practices in the florida keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. poorly treated sewage is thus released into the highly porous subsurface key largo limestone matrix. to investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injecti ... | 1995 | 16535046 |
| the bacteriophage prd1 uses a pseudo-beta propeller to bind to its cellular receptor. | | 2003 | 12623009 |
| structure of a197 from sulfolobus turreted icosahedral virus: a crenarchaeal viral glycosyltransferase exhibiting the gt-a fold. | sulfolobus turreted icosahedral virus (stiv) was the first icosahedral virus characterized from an archaeal host. it infects sulfolobus species that thrive in the acidic hot springs (ph 2.9 to 3.9 and 72 to 92 degrees c) of yellowstone national park. the overall capsid architecture and the structure of its major capsid protein are very similar to those of the bacteriophage prd1 and eukaryotic viruses paramecium bursaria chlorella virus 1 and adenovirus, suggesting a viral lineage that predates t ... | 2006 | 16840342 |
| the receptor binding protein p2 of prd1, a virus targeting antibiotic-resistant bacteria, has a novel fold suggesting multiple functions. | bacteriophage prd1 is unusual, with an internal lipid membrane, but has striking resemblances to adenovirus that include receptor binding spikes. the prd1 vertex complex contains p2, a 590 residue monomer that binds to receptors on antibiotic-resistant strains of e. coli and so is the functional counterpart to adenovirus fiber. p2 structures from two crystal forms, at 2.2 and 2.4 a resolution, reveal an elongated club-shaped molecule with a novel beta propeller "head" showing pseudo-6-fold symme ... | 2003 | 12623018 |
| efficient dna packaging of bacteriophage prd1 requires the unique vertex protein p6. | the assembly of bacteriophage prd1 proceeds via formation of empty procapsids containing an internal lipid membrane, into which the linear double-stranded dna genome is subsequently packaged. the packaging atpase p9 and other putative packaging proteins have been shown to be located at a unique vertex of the prd1 capsid. here, we describe the isolation and characterization of a suppressor-sensitive prd1 mutant deficient in the unique vertex protein p6. protein p6 was found to be an essential par ... | 2007 | 17202207 |
| probing the ability of the coat and vertex protein of the membrane-containing bacteriophage prd1 to display a meningococcal epitope. | bacteriophage prd1 is an icosahedral dsdna virus with a diameter of 740 a and an outer protein shell composed of 720 copies of major coat protein p3. spike complexes at the vertices are composed of a pentameric base (protein p31) and a spike structure (proteins p5 and p2) where the n-terminal region of the trimeric p5 is associated with the base and the c-terminal region of p5 is associated with receptor-binding protein p2. the functionality of proteins p3 and p5 was investigated using insertion ... | 2003 | 12781714 |
| virus removal from wastewater in a multispecies subsurface-flow constructed wetland. | virus removal was studied in a multispecies subsurface-flow constructed wetland. tracer studies and a virus survival test were conducted using bromide and bacteriophage prd1 that were simultaneously added into a 6-year-old gravel-filled wetland. the estimated dimensionless variance and the observed bromide breakthrough curve suggest a plug-flow reactor with some dispersion. most of the prd1 was removed during the first 4 days; however, the prd1 background concentration was not reached by the end ... | 2003 | 12837030 |
| identification and functional analysis of the rz/rz1-like accessory lysis genes in the membrane-containing bacteriophage prd1. | bacteriophage prd1 is a tailless membrane-containing double-stranded (ds) dna virus infecting a variety of gram-negative bacteria. in order to affect cell lysis, like most dsdna phages, prd1 uses the holin-endolysin system. in this study, we identified two accessory lysis genes, xxxvi and xxxvii, coding for proteins p36 and p37, respectively. using genetic complementation assays, we show that protein pair p36/p37 is a functional and interchangeable analogue of the rz/rz1 of bacteriophage lambda. ... | 2008 | 18366440 |
| pgil01, a linear tectiviral plasmid prophage originating from bacillus thuringiensis serovar israelensis. | bacillus thuringiensis serovar israelensis harbours, in addition to several circular plasmids, a small linear molecule of about 15 kb. sequence analysis of this molecule, named pgil01, showed the presence of at least 30 orfs, five of which displayed similarity with proteins involved in phage systems: a b-type family dna polymerase, a lexa-like repressor, two potential muramidases and a dna-packaging protein (distantly related to the p9 protein of the tectiviral phage prd1). experimental evidence ... | 2003 | 12904548 |
| viral evolution revealed by bacteriophage prd1 and human adenovirus coat protein structures. | the unusual bacteriophage prd1 features a membrane beneath its icosahedral protein coat. the crystal structure of the major coat protein, p3, at 1.85 a resolution reveals a molecule with three interlocking subunits, each with two eight-stranded viral jelly rolls normal to the viral capsid, and putative membrane-interacting regions. surprisingly, the p3 molecule closely resembles hexon, the equivalent protein in human adenovirus. both viruses also have similar overall architecture, with identical ... | 1999 | 10499799 |
| systematic study of effects of ph and ionic strength on attachment of phage prd1. | objectives of this work are to investigate effects of ph and ionic strength (is) on virus transport in saturated soil and to develop a quantitative relationship for these effects. a series of 50-cm column experiments with clean quartz sand under saturated conditions and with ph values of 5, 6, 7, 8, and is values of 1, 10, and 20 mm were conducted. bacteriophage prd1 was used as a model virus. applying a one-site kinetic model, attachment, detachment, and inactivation rate coefficients were dete ... | 2010 | 21039452 |
| stable packaging of phage prd1 dna requires adsorption protein p2, which binds to the incp plasmid-encoded conjugative transfer complex. | the double-stranded dna bacteriophage prd1 uses an incp plasmid-encoded conjugal transfer complex as a receptor. plasmid functions in the prd1 life cycle are restricted to phage adsorption and dna entry. a single phage structural protein, p2, located at the fivefold capsid vertices, is responsible for prd1 attachment to its host. the purified recombinant adsorption protein was judged to be monomeric by gel filtration, rate zonal centrifugation, analytical ultracentrifugation, and chemical cross- ... | 1999 | 10542170 |