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[transgenosis with participation of plasmid rp1; indications of the presence of a "composit plasmid" in an interspecies hybrid of escherichia coli].one of the transconjugants (1-7) obtained by the authors earlier in the conjugation of escherichia coli j-62 with pseudomonas aeruginosa 1822, besides the plasmic rp1 has acquired the ability to grow without proline and tryptophan. the detailed analysis has shown that in the conjugation of the transconjugant 1-7 with different strains of e. coli the plasmic rp1 and chromosomal genes were transmitted together, but in transduction--by means of bacteriophage p1, independently of each other. the fer ...1977410469
superinfection immunity and prophage repression in phage p1 and p7. iii. induction by virulent mutants. 1977860403
a phage p1 virulent mutation at a new map location. 1977860411
plaque forming specialized transducing phage p1: isolation of p1cmsmsu, a precursor of p1cm. 1977895711
physical mapping of bglii, bamhi, ecori, hindiii and psti restriction fragments of bacteriophage p1 dna.a cleavage map of bacteriophage p1 dna was established by reciprocal double digestion with various restriction endonucleases. the enzymes used and, in parenthesis, the number of their cleavage sites on the p1clts genome are: psti (1), hindiii(3), bglii (11), bamhi (14) and ecori (26). the relative order of the psti, hindiii and bglii sites, as well as the order of 13 out of the 14 bamhi sites and of 17 out of the 26 ecori sites was determined. the p1 genome was divided into 100 map units and the ...1977895712
miniplasmids of bacteriophage p1. i. stringent plasmid replication does not require elements that regulate the lytic cycle. 1978642010
superinfection immunity and prophage repression in phage p1. iv. the c1 repressor bypass function and the role of c4 repressor in immunity. 1978664217
salmonella typhimurium mutants lacking protease ii.mutants of salmonella typhimurium lacking protease ii, an endoprotease with trypsin-like specificity, have been isolated. these mutants can be identified by using the chromogenic substrate n-methyl-n-p-toluenesulfonyl-l-lysine beta-naphthyl ester to screen colonies growing on agar for the presence of the enzyme. all of the mutations isolated map at locus tlp (typsin-like protease) which is cotransducible (approximately 1%) using phage p1 with tre (trehalose utilization) at approximately 58 min o ...1978355236
acylaminoacid esterase mutants of salmonella typhimurium.salmonella typhimurium contains three electrophoretically separable enzyme activities that hydrolyze n-acetyl phenylalanine beta-naphthyl ester (napne). one of these enzymes is an endoprotease, protease i. mutations at a locus apea near pure lead to loss of this enzyme. we have found that n-acetyl leucine alpha-naphthyl ester (nalne) is not hydrolyzed by protease i but is a good substrate for the other two activities. using nalne as a chromogenic substrate to screen colonies growing on agar, we ...1978360040
a second transport system for sn-glycerol-3-phosphate in escherichia coli.strains containing phage mucts inserted into glpt were isolated as fosfomycin-resistant clones. these mutants did not transport sn-glycerol-3-phosphate, and they lacked glpt, a protein previously shown to be a product of the glpt operon. by plating these mutants on sn-glycerol-3-phosphate at 43 degrees c, we isolated revertants that regained the capacity to grow on g3p. most of these revertants did not map in glpt and did not regain glpt. these revertants exhibited a highly efficient uptake syst ...1978363686
analysis of bacteriophage p1 immunity by using lambda-p1 recombinants constructed in vitro.we describe the dissection and reconstruction of a complex control circuit, the p1 immunity system, by a method that involves inserting ecori-generated fragments of p1 dna into lambda vectors that can then be sequentially inserted into a bacterial cell. using these techniques we have isolated lambda-p1 hybrid phages that express the products of p1 genes c1, c4, ant, and ban and, in appropriately constructed lysogens, confirmed the roles played by the first three of these products in phage immuni ...1978364485
[regulation of the activity of escherichia coli deo-operon structural genes: the mutation mapped within the operon boundaries and affecting drm and pup gene activity].the mutant air38 is isolated from escherichia coli k-12 strain deficient in thymidilate synthetase and deoxyriboaldolase (hfrh, thy, dra)--by selection for low thymine requirement on the medium containing inosine as the carbon source. under the conditions mentioned the mutant air38 (thy, dra) grows at low thymine concentration (2 mkg/ml), and is uncapable to grow in the presence of thymidine (40 mkg/ml). dra+ derivatives of the air38 do no catabolize inozine in the presence of thymidine as well. ...1978369945
chromosomal location of the mop (groe) gene necessary for bacteriophage morphogenesis in escherichia coli.the chromosomal location of a host gene, mop (groe), which is essential for the morphogenesis of several bacteriophages in escherichia coli, was determined by two- and three-factor transductional crosses using phage p1. cotransduction frequencies beteen mop and other markers were: aspa, 90%; ampa, 77%; frda, 73%; mel, 24%. the sequence of markers in the corresponding segment (mel to pura; 91.5 to 93.5 min) of the e. coli linkage map was shown to be mel--aspa--mop(groe)--ampa--frda--pur a.1978370345
a model for plasmid maintenance of bacteriophage p1.studies of the stability of p1 plasmid in a p1 cry escherichia coli lysogen have suggested a model for equipartition of plasmid copies. equipartition might be controlled by the detachment of p1 copies after replication, followed by their reattachment to membrane sites, in coordination with bacterial division.1978371479
suppression of a thermosensitive dnaa mutation of escherichia coli by bacteriophage p1 and p7. 1978372960
the biochemical and genetic basis for high frequency thiomethyl galactoside resistance in lambda,lambdadg lysogens of escherichia coli.in a culture of escherichia coli k12 gal (lambdadg), cells which form large colonies on agar plates containing galactose and thiomethyl beta-d-galactoside (tmg) appear at high frequency. these clones are resistant to growth inhibition by tmg on galactose minimal medium. biochemical studies of the steady-state levels of galactokinase and udpgalactose 4-epimerase suggest that the resistant clones have extra copies of the genes for the galactose-metabolizing enzymes. the mutation for tmg resistance ...1978344832
glutamine synthetase of klebsiella aerogenes: properties of glnd mutants lacking uridylyltransferase.the glnd mutation of klebsiella aerogenes is cotransducible by phage p1 with pan (requirement for pantothenate) and leads to a loss of uridylytransferase and uridylyl-removing enzyme, components of the glutamine synthetase adenylylation system. this defect results in an inability to deadenylylate glutamine synthetase rapidly and in a requirement for glutamine for normal growth. suppression of the glnd mutation are located at the glutamine synthetase structural gene glna.197826659
regulation of glutamine synthetase formation in escherichia coli: characterization of mutants lacking the uridylyltransferase.a lambda phage (lambdank55) carrying the translocatable element tn10, conferring tetracycline resistance (tetr), has been utilized to isolate glutamine auxotrophs of escherichia coli k-12. such strains lack uridylyltransferase as a result of an insertion of the tn10 element in the glnd gene. the glnd::tn10 insertion has been mapped at min 4 on the e. coli chromosome and 98% contransducible by phage p1 with dapd. a lambda transducing phage carrying the glnd gene has been identified. a glnd::tn10 ...197826660
escherichia coli mutants deficient in deoxyuridine triphosphatase.mutants deficient in deoxyuridine triphosphatase (dutpase) were identified by enzyme assays of randomly chosen heavily mutagenized clones. five mutants of independent origin were obtained. one mutant produced a thermolabile enzyme, and it was presumed to have a mutation in the structural gene for dutpase, designated dut. the most deficient mutant had the following associated phenotypes: less than 1% of parental dutpase activity, prolonged generation time, increased sensitivity to 5'-fluorodeoxyu ...1978148458
a dnab-analog dna-replication protein of phage p1. 1979157840
cloning and physical mapping of the dnaa region of the escherichia coli chromosome.the dnaa gene of escherichia coli k-12, supposedly present in the deoxyribonucleic acid (dna) of specialized transducing phase lambda i21 dnaa-2, was cloned onto plasmid pbr322. the new plasmid was named pmcr501. physical analyses of dnas of lambda i21 dnaa-2 and pmcr501 revealed the following. the lambda i21 dnaa-2 dna retained the delta sr i lambda 1-2 and ninr5 deletions and imm21 substitution which were originally present in the parental phage. the size reduction was compensated for by the i ...1979160412
regulatory circuits in bacteriophage p1 as analyzed by physical dissection and reconstruction. 1979161219
deletion mapping of the pola-metb region of the escherichia coli chromosome.a lambdaci857 prophage inserted into one of the genes of the rha locus was used to select deletions unambiguously ordering the markers pola-glna-rha-pfka-tpi-metbjf. transduction with phage p1 indicates at least 70% linkage between glna and pola. the order of the pfk and tpi markers is reversed from that previously published. despite the relatively large distance separating the glna and rha loci, deletions removing this entire region have no obvious phenotype. the isolation of tn10 transposons i ...197935528
mapping of ilvo loci of escherichia coli k-12 with bacteriophage lambda dilv.a set of lambda dilv phage have been used in a deletion mapping procedure to determine the location of two previously characterized ilvo alleles. in contrast to earlier conclusions derived from three-factor crosses and episome-shortening techniques with phage p1, the order found is ilvg-ilvo-ilveda. a three-factor cross with phage p1 is described that is not consistent with this location for an ilvo allele. further analysis of this particular three-factor cross revealed than an artifact attribut ...1979374344
chloramphenicol resistance mutation in escherichia coli which maps in the major ribosomal protein gene cluster.localized mutagenesis and selection for streptomycin resistance were utilized to isolate a chloramphenicol resistance mutation in escherichia coli k-12 linked to the stra (rpsl) locus. bacteriophage p1 transduction verified the map position of the new resistance mutation at 72 min, placing it within a dense cluster of ribosomal protein genes. the map position differs from that of known cmla and cmlb mutations, which map at 18 and 21 min, respectively. ribosomes prepared from chloramphenicol-resi ...1979374348
regulation of nonspecific acid phosphatase in salmonella: phon and phop genes.mutations in salmonella typhimurium strains lacking nonspecific acid phosphatase mapped in two unlinked loci. one of these, phop, was cotransducible by phage p22 with purb, whereas the second, phon, was cotransducible by phage p1 with pura. mutants with temperature-sensitive nonspecific acid phosphatase activity (measured in whole cells) were also isolated. a phon mutant with thermolabile whole-cell activity was isolated directly from wild-type lt-2. several other mutants with temperature-sensit ...1979374361
genetic studies of an escherichia coli k-12 temperature-sensitive mutant defective in membrane protein synthesis.the mutant dive42(ts) of escherichia coli k-12, defective in the synthesis of membrane proteins and in the transcription of the lac operon at high temperature, has been further characterized. it was found that a mutation (dive42) located at about min 22 on the e. coli chromosome map is responsible for the lac- phenotype and temperature-sensitive growth. the mutation could be contransduced with serc, pyrd, or pyrc by phage p1 at a frequency of 4, 16, or 0.5%, respectively, the gene order being se ...1979374381
non-random distribution of transduction termini in transductants from the integrated r plasmid, r100-1.tra+ and tra- derivatives of drug resistance plasmid, r100-1, were isolated by phage p1 from an hfr donor with integrated r100-1 and then analyzed by complementation tests with tra- point mutants of flac. tra+ derivatives of r100-1 carrying tetracycline resistance alone and those carrying all six drug-resistrance genes could support transfer of tra- point mutants of flac except flac traj, whereas all of tra- derivatives of r100-1 failed to complement any one of tra- point mutants of flac. this s ...1979375027
chromosomal location and expression of the structural gene for major outer membrane protein ia of escherichia coli k-12 and of the homologous gene of salmonella typhimurium.the gene determining the structure of a major outer membrane protein of escherichia coli, protein ia, has been located between serc and pyrd, at the min 21 region of the linkage map. this is based on the isolation and characterization of e. coli-salmonella typhimurium intergeneric hybrids as well as analyses of a mutation (ompf2) affecting the formation of protein ia. when the serc region of the s. typhimurium chromosome was transduced by phage p1 into e. coli, two classes of transductants were ...1979378974
rearrangements of genetic material in escherichia coli as observed on the bacteriophage p1 plasmid. 1979385224
a dnab analog ban, specified by bacteriophage p1: genetic and physiological evidence for functional analogy and interactions between the two products.bacteriophage p1 has been shown previously to determine a product ban that can substitute in dna replication for the protein specified by cis-tron dnab of escherichia coli. however, ban product furnished by p1 bac prophage (ban constitutive) substitutes only poorly for dna replication in the absence of dnab product in a strain bearing an unsuppressed amber mutation, dnab266, as shown by the cryosensitivity of the dnab266 (p1 bac) lysogen and its unability to support lambda growth. an additional ...1979386042
a new pleiotropic bacteriophage p1 mutation, bof, affecting c1 repression activity, the expression of plasmid incompatibility and the expression of certain constitutive prophage genes.in bacteriophage p1 an amber mutation in a new gene, bof, has been isolated. the bof-1 phage mutant exhibits a pleiotropic phenotype; bof product is non-essential, and acts as a positive modulator. in p1 bac-1 mutants, in which a dnab analog product, ban, is expressed constitutively, the bof product activates ban expression both in the prophage state and in lytic growth: p1 bof bac prophages have a reduced ban activity and in lytic growth p1 bof bac phages show a lower ban activity than p1 wild ...1979386043
mapping of a new hem gene in escherichia coli k12.a new type of haem-deficient mutant was isolated in escherichia coli k12 by neomycin selection. the mutant, designated sasx38, accumulated uroporphyrin, coproporphyrin and protoporphyrin. since it possessed normal ferrochelatase activity, it was assumed to be deficient in protoporphyrinogen oxidase activity. the gene affected in the mutant was designated hemg. mapping of the hemg gene by phage p1-mediated transduction showed that it was located very close to the chlb gene (frequency of cotransdu ...1979390093
isolation and characterization of dnax and dnay temperature-sensitive mutants of escherichia coli.escherichia coli mutants with temperature-sensitive (ts) mutations in dnax and dnay genes have been isolated. based on transduction by phage p1, dnax and y have been mapped at minutes 10.4--10.5 and 12.1, respectively, in the sequence dnax pure dnay. both dna xts36 and yts10 are recessive to wild-type alleles present on episomes. f13 carries both dnax+ and y+; the shorter f210 carries dnay+, but not x+. lambda tranducing phages that carry dnax+ or y+ have been isolated, and hybrid plasmids of co ...1979391641
escherichia coli mutants incapable of supporting replication of f-like plasmids at high temperature: isolation and characterization of mafa and mafb mutants.mutants of escherichia coli k-12 defective in replication of f-like plasmids at a high temperature (42 degrees c) were found among threonine-independent (thr+) revertants of a threonine-requiring f' stain after localized mutagenesis with n-methyl-n'-nitro-n-nitrosoguanidine. transduction experiments with phage p1 permitted us to divide these mutations into two classes with respect to man location; some mutations were located between thr and ara at about 0.8 min, very close to maf-1 reported prev ...1979391803
replication and gene functions of the bacteriocinogenic plasmid clodf13.the replication and genetic constitution of plasmid clodf13 was studied using mutants of clodf13 obtained by ntg mutagenesis, insertion of the ampicillin transposon tn901, or deletion of particular clodf13 dna regions. analysis of the polypeptides encoded by these mutant plasmids enabled us to locate six genes on the clodf13 physical map. these genes cover about 60% of the coding capacity of clodf13. a large part of the clodf13 genome (about 30%) is involved in the conjugal transfer of this plas ...1979394925
multiple physical differences in the genome structure of functionally related bacteriophages p1 and p7.comparative restriction cleavage analysis of the genomes of bacteriophage p7, of several recombinant phages between p7 and p1, and of bacteriophage p1 allowed to draw psti, bg/ii, bamhi and hindiii cleavage maps of all genomes studied. the data obtained complement yun and vapnek's (1977) conclusions with regard to areas of major nonhomology based on electron microscopical heteroduplex analysis and they identify several additional minor differences between p1 and p7. the use of hybrid phage strai ...1979289897
isolation and characterization of cloned fragments of bacteriophage p1 dna. 1979452412
a characterization of bacteriophage p1 dna fragments cloned in a lambda vector. 1979462805
an escherichia coli mutant defective in single-strand binding protein is defective in dna replication.an escherichia coli mutant, temperature-sensitive for dna synthesis in vivo and in vitro, is defective in single-strand binding protein (ssb; dna-binding protein). conversion of phage g4 single strands to the duplex form is defective in crude enzyme fractions of the mutant and is complemented by pure wild-type ssb. radioimmunoassays of mutant extracts show normal levels of material crossreacting with anti-ssb antibody. ssb purified to homogeneity from the mutant is active, with lower specific ac ...1979221903
altered phospholipid composition in mutants of escherichia coli sensitive or resistant to organic solvents.mutants of escherichia coli with altered resistance to low molecular weight organic solvents were isolated. solvent-resistant mutants showed a decrease in the ratio of phosphatidylethanolamine to the anionic phospholipids (phosphatidylglycerol and cardiolipin) relative to the wild-type, whereas solvent-sensitive strains showed an increase. reversion studies on representative mutants demonstrated that the phenotypic response to solvents and the changes in phospholipid composition were genetically ...197992527
on the role of is1 in the formation of hybrids between the bacteriophage p1 and the r plasmid nr1. 19806245339
bacteriophage p1 as a vehicle for mu mutagenesis of salmonella typhimurium.we developed a procedure using bacteriophage p1 as a vector for transferring mu phage deoxyribonucleic acid into salmonella typhimurium. mu phage transferred in this manner yielded lysogenic auxotrophs, and we demonstrated that specific deletions and lac gene fusions can be selected.19806253444
a cointegrate of the bacteriophage p1 genome and the conjugative r plasmid r100. 19806100897
transposon mutagenesis of the gene encoding the bacteriophage p1 restriction endonuclease. co-linearity of the gene and gene product. 19806265645
naturally occurring r.colbm plasmids belonging to the incfiii incompatibility group.two escherichia coli strains isolated from urinary tract infections were resistant to streptomycin, kanamycin, neomycin, tetracycline and sulphonamides. the strains also produced colicins b and m. the resistance to streptomycin, kanamycin and neomycin and the ability to produce colicins b and m could be transferred to an e. coli k12 recipient. resistance and colicinogeny markers were transferred together by conjugation, and did not segregate even after interrupted mating or phage p1-mediated tra ...19807014768
a circular form of bacteriophage p1 dna made in lytically infected cells of escherichia coli. characterization and kinetics of formation. 19806986712
synthesis of p1 ban protein in minicells infected by p1 mutants.phage p1 encodes a dnab analog (ban) protein. synthesis of ban protein has been studied in minicells infected by p1 mutants and has been identified as a polypeptide of 56,000 molecular weight by immunoprecipitation using antibody directed against e. coli dnab protein. the amount of ban protein synthesized by p1 mutants increases in the order: p1 wild type, p1bac, p1crr, and p1bac crr. the relative amount of ban protein identified in p1bac- and p1bac crr-infected minicells is approximately the s ...19806988666
genetic analysis of a pleiotropic mutant of klebsiella pneumoniae affected in nitrogen metabolism.genetic and reversion analyses of a thermosensitive pleiotropic mutant strain of klebsiella pneumoniae with defects in nitrogen fixation and nitrogen metabolism have shown that the pleiotropie behaviour of mutant is due to a single mutation in a gene designated nim. this gene is contransducible with trp at a frequency of about 30% (using bacteriophage p1) and with cys at a frequency of about 14%. the gene order is cys, trp, nim. the defect in the nim mutant is complemented by the e. coli f' elem ...19806989957
identification of the repressor and repressor bypass (antirepressor) polypeptides of bacteriophage p1 synthesized in infected minicells.p1 infected minicells synthesize approximately 50 phage-encoded polypeptides. phage expression is temporally controlled, demonstrating phage polypeptides synthesized both early and late after infection. the p1 repressor, gpcl1 (mr = 33,000), repressor bypass polypeptide, gpreb a (mr = 27,500) and cistron 10 product, (gp10) (mr = 64,000), have been identified by infection of minicells with p1 amber mutants. the beta-lactamase gene product (gpbla) carried by the closely related p7 and the chloramp ...19806991877
a dnab analog function specified by bacteriophage p7 and its comparison to the similar function specified by bacteriophage p1.evidence is presented that bacteriophage p7 specifies an analog of the e. coli dna replication protein, dnab. as in the related bacteriophage p1 (d'ari et al., 1975; ogawa, 1975), in lysogens of p7, the production of the analog protein is repressed and constitutive mutants could be isolated. such constitutive mutants could suppress efficiently the thermosensitivity of several dnab(ts) mutations and also rescue a strain carrying a dnab amber mutation. while neither p7 nor the mutant p1bacban (def ...19806993853
enterotoxigenic escherichia coli carrying plasmids coding for antibiotic resistance and enterotoxin production.nine strains of enterotoxigenic escherichia coli that were resistant to antibiotics were tested for their ability to transfer both antibiotic resistance and enterotoxigenicity to e. coli k12. all nine isolates transferred antibiotic resistance in bacterial conjugation experiments, and in seven of these matings enterotoxigenicity was also transferred. to determine whether the genetic information coding for the production of enterotoxin and antibiotic resistance was located on the same plasmid in ...19806997407
phage p1 temperature-sensitive mutants with defects in the lytic pathway. 19806998105
bacteriophage p1-mediated generalized transduction in escherichia coli: fate of transduced dna in rec+ and reca- recipients. 19806998106
bacteriophage p1-mediated generalized transduction in escherichia coli: structure of abortively transduced dna. 19806998107
mapping of the pola locus of escherichia coli k12: genetic fine structure of the cistron.the close linkage of the glna gene with pola was exploited to construct a fine structure map of pola by means of generalized transduction with phage p1. nine different pola- alleles were mapped by recombinational crosses. the results indicate a gene order consistent with previous observations (kelley and grindley 1976a; murray and kelley 1979). three mutations, pola5, pola6 and pola12 map within the "carboxy-terminal" or "large-fragment" portion of the gene in unambiguous order. four alleles, kn ...19807000617
the c1 repressor of bacteriophage p1. i. isolation of the c1 protein and determination of the p1 dna region to which it binds. 19807001033
[intergeneric crossing: p1 phage transduction of the malb region in crosses between e. coli and s. typhimurium].in the intergeneric crossing of e. coli and s. typhimurium, no effective transduction of the malb gene was observed. the absence of effective transduction suggests the low homology of the malb chromosomal areas in e. coli and s. typhimurium. to carry out the transduction of the malb gene together with the lexa gene from e. coli to s. typhimurium, a hybrid having no restriction of phage p1 and incorporating the malb area of e. coli should be previously created.19807004022
the variation in frequency with which markers are transduced by phage p1 is primarily a result of discrimination during recombination.the efficiency of recovery of p1 transductants is marker dependent and normally varies over a 25-fold range. uv irradiation of either transducing lysates for recipient cells results in a selective stimulation of the transduction of markers which are normally transduced poorly. as a result the range in frequency of transduction is reduced to about 3-fold and resembles the gene frequency distribution expected in the donor cells. we conclude that p1 transducing lysates are likely to contain a rando ...19807007821
genetic and physiological characterization of a spontaneous mutant of escherichia coli b/r with aberrant control of deoxyribonucleic acid replication.strain tjk16, a low-thymine-requiring thya deob derivative of escherichia coli b/r a, was found to have an increased initiation mass due to a mutation in a gene affecting the control of initiation of deoxyribonucleic acid replication. in contrast to temperature-sensitive initiation mutants, initiation in tjk16 was not temperature sensitive. by phage p1 transduction, it was found that the mutation lies within a small region of the chromosome between dnaa and gyrb; this region includes dnan and re ...19817009574
genetic studies of h group plasmids by bacteriophage p1 transduction.bacteriophage p1 transduction was used to study the incompatibility group h1 plasmid prg1251, molecular weight 120 x 10(6), and the incompatibility group h2 plasmid psd114, molecular weight 166 x 10(6). the order of resistance (r) determinants on psd114 was deduced from transduction and segregation experiments to be chloramphenicol-tetracycline-kanamycin-streptomycin. resistance to tellurium and to coliphages, which are properties also encoded by many h2 plasmids, were not transduced with the ot ...19817011519
[lethal and mutagenic action of uv light on salmonellae carrying wild or mutant alleles of the escherichia coli lexa-gene].to elucidate the reasons for the absence of uv-mutability in salmonella typhimurium, the lexa gene of escherichia coli has been transduced by phage p1 into s. typhimurium. the functioning of lexa+ allele of e. coli in the chromosome of salmonella failed to cause uv-mutability of the hybrid. the transfer of pkm101 plasmid into the lexa+ hybrid mediates the expressed uv mutability and uv-protective plasmid effect. this plasmid harboured by the lexa hybrid fails to increase uv-resistance and mutabi ...19817014362
suppression of dnac alleles by the dnab analog (ban protein) of bacteriophage p1.the dnab analog protein produced by the ban gene of bacteriophage p1 was shown to suppress several escherichia coli dnac alleles. suppression of dnac7 temperature sensitivity in p1 lysogens of a dnac7 mutant was complete at all temperatures. for the dnac2 and dnac28 alleles, suppression was observed only at intermediate temperatures. though these intermediate temperatures were sufficient to completely restrict the mutants, at higher temperatures the suppression was not observed. no suppression o ...19817217002
characterization of bacteriophage j2 of salmonella typhi as a generalized transducing phage closely related to coliphage p1.phage j2, a lysogenic phage in salmonella typhi j2, was shown to produce tiny plaques on various vi type strains of s. typhi, to be a generalized transducing phage, and to have many characteristics including a serological one in common with phage p1 of escherichia coli. lysogenization of various s. typhi type strains with j2 or p1-group phages usually resulted in the alteration of the phage types of the s. typhi strains, except that phage j2 did not cause alteration of type 53. phage j2 transduc ...19817338730
genetic mapping of a mutation conferring sensitivity to bacteriophage mu in salmonella typhimurium lt2.two strains of salmonella typhimurium lt2, sa1475 and ma411, were fortuitously found to be sensitive to bacteriophage mu. the mu-sensitivity allele of sa1475 was called musa1 and shown to be linked to the histidine operon both in conjugation and transduction experiments. the mus allele of ma411 was unlinked to the his region and was tentatively designated musb2. strains carrying large deletions of the his operon were also tested for mu sensitivity; those of which the his-rib region is deleted we ...19817016837
high-affinity arabinose transport mutants of escherichia coli: isolation and gene location.the gene araf, the product of which is the l-arabinose-binding protein--a component of the high-affinity l-arabinose transport system, was located on the escherichia coli linkage map at 45 min. we established this location using bacteriophage p2 eductates and bacteriophage p1 cotransduction frequencies with the adjacent genetic loci, his (histidine biosynthesis) and mgl (methylgalactoside transport). in addition, we isolated a number of mutants that phenotypically exhibited altered high-affinity ...19817024251
a novel role for site-specific recombination in maintenance of bacterial replicons.if daughter copies of unit-copy replicons recombine with each other, a replicon dimer results that cannot be partitioned equally to daughter cells at cell division. we present evidence that dimer formation interferes with plasmid equipartition in the case of a miniplasmid derived from the unit-copy plasmid prophage of bacteriophage p1. asymmetric partition occurs, leading to a relatively high rate of loss of the plasmid from the growing population. in contrast, the wild-type p1 plasmid is mainta ...19817026049
control of circularization of bacteriophage p1 dna in escherichia coli. 19817027600
surface exclusion between f' plasmids in strains of escherichia coli k-12 carrying a dnab mutation, in the presence or absence of bacteriophage genomes providing a dnab analog function.in a set of isogenic strains, three out of four different dnab(ts) mutations reduced surface exclusion between f' plasmids. in further studies with a strain carrying one of these mutations (dnab43), surface exclusion remained reduced in the presence of a recombinant plasmid carrying only the region of f that encodes the surface exclusion proteins trasp and tratp. the dnab analog specified by bacteriophage p1 but not that specified by p7 increased the surface excluding ability of the strain carry ...19817035825
the isolation and characterization of escherichia coli dnab::tn10 insertion mutations.exploitation of the ability of the ban protein encoded by phage p1 to compensate for dnab-defective host mutations, allowed the isolation of dnab::tn10 insertion mutations. the presence of p1bac prophage was required for survival of dnab::tn10 mutants, and such lysogens were cryosensitive. the insertions were shown to map in dnab by transduction and this was confirmed by complementation analysis. the dnab::tn10 (p1bac) strains were non-permissive for lambda growth but did support the growth of l ...19816267428
characterization of p1argf derivatives from escherichia coli k12 transduction. i. is1 elements flank the argf gene segment.specialized transducing derivatives of the temperate bacteriophage p1 (p1std) are selected by transduction into recipients with deletions in the corresponding genes (stodolsky 1973). when escherichia coli k12 strains are used as donors in such transduction experiments, p1argf derivatives can be selected. the argf gene is unique to these strains (glansdorff et al. 1967). under these experimental conditions p1argf are formed with frequencies 10,000 times greater than other p1std. the majority of t ...19816268940
genesis and natural history of is-mediated transposons.the natural genesis of is1-mediated transposons containing the genetic determinant cat for chloramphenicol resistance is documented. first, the small plasmid pbr325 containing the cat gene served as a target in is1-mediated transpositional cointegration with the genome of bacteriophage p1, which was the source of the is1. from the resulting pbr325:p1 plasmids, pbr325::is1 segregants were isolated. upon growth of a phage lambda derivative in the presence of this plasmid, rare plaque-forming lambd ...19816271475
cointegrates between bacteriophage p1 dna and plasmid pbr322 derivatives suggest molecular mechanisms for p1-mediated transduction of small plasmids.we characterized cointegrates formed in an escherichia coli rec+ strain between bacteriophage p1 genomes and small plasmids related to pbr322. the partners were, on the one hand, either phage p1 dna, which carries one copy of is1, or phage p1-15 dna, a derivative which lacks the is1, and, on the other hand, plasmids containing either a split is1 or no. in the presence of is1 sequences on both partners, cointegrates were usually formed by reciprocal recombination between si1 sequences. cointegrat ...19816278242
is the is1-flanked r-determinant of the r plasmid nr1 a transposon?the 23 kilobase multiple drug resistance r-determinant (r-det) of the r plasmid nr1 is an is1-mediated transposon, tn2671. drug-resistant escherichia coli transductants isolated after infection with bacteriophage p1::tn2671 derivatives carry the intact r-det in their chromosomes. independently isolated transductants carry the r-det at different locations on the chromosome. from the e. coli chromosome, tn2671 can transpose to various locations on the phage p7 genome. throughout these processes, r ...19816279762
bacteriophage p1 site-specific recombination. i. recombination between loxp sites. 19816276557
bacteriophage p1 site-specific recombination. ii. recombination between loxp and the bacterial chromosome. 19816276558
a nonsense mutation in bacteriophage p1 eliminates the synthesis of a protein required for normal plasmid maintenance. 19816454157
site-specific recombination and its role in the life cycle of bacteriophage p1. 19816457723
bacteriophage p1 site-specific recombination. iii. strand exchange during recombination at lox sites. 19816460113
denaturation map of bacteriophage p1 dna. 19816259828
introduction of transposon tn5 into myxococcus for analysis of developmental and other nonselectable mutants.the transposon tn5, which carries a gene for kanamycin resistance, can be introduced into myxococcus xanthus, an organism that undergoes a primitive cycle of development, from escherichia coli by the specialized transducing phage p1::tn5. tn5 dna sequences, but no p1 sequences, are found in the stable kanamycin-resistant transductants. tn5 transposes from p1 to many different chromosomal sites in myxococcus. in each independent transductant of myxococcus examined, the tn5 element is found in a d ...198116592958
effects of glnl and other regulatory loci on regulation of transcription of glna-lacz fusions in klebsiella aerogenes.mutants of klebsiella aerogenes containing genetic fusions of glna to lacz were isolated by using mu dl (lac, bla) bacteriophage and a mu kmr helper phage with the host range of bacteriophage p1. synthesis of beta-galactosidase in these strains is regulated in response to nitrogen metabolites and regulatory gln loci and is rendered constitutive by a mutation in the linked glnl gene. complementation studies indicated that glnl is a separate locus from glna and glng and that insertions in glna are ...19826120932
genetic and physical map of a p1 miniplasmid.the prophage form of bacteriophage p1 is a unit-copy plasmid which is maintained with great fidelity in its escherichia coli host. the plasmid maintenance functions of p1 are clustered in one region of the genome. an 11.5-kilobase fragment from this region has been cloned into a lambda delta att vector and promotes stable unit-copy plasmid maintenance. the properties of the lambda vector facilitated the isolation of deletion mutants affecting the p1 dna. twenty-eight deletion mutants were isolat ...19826749822
characterization of escherichia coli men mutants defective in conversion of o-succinylbenzoate to 1,4-dihydroxy-2-naphthoate.four independent menaquinone (vitamin k(2))-deficient mutants of escherichia coli, blocked in the conversion of o-succinylbenzoate (osb) to 1,4-dihydroxy-2-naphthoate (dhna), were found to represent two distinct classes. enzymatic complementation was observed when a cell-free extract of one mutant was mixed with extracts of any of the remaining three mutants. the missing enzymes in the two classes were identified by in vitro complementation with preparations of osb-coenzyme a (coa) synthetase or ...19826754698
dna replication and indirect induction of the sos response in escherichia coli.the sos response can be induced indirectly in escherichia coli by infection with uv irradiated bacteriophage p1, lambda or m13. induction, monitored quantitatively by means of a sfia::lac operon fusion, was stronger with the plasmid phage p1 than with lambda, but the kinetics were similar, showing that plasmid and non-plasmid phages are not fundamentally different in their ability to produce indirect induction. in the absence of lambda dna replication the level of induction was strongly reduced, ...19826814510
determining the phom map location in escherichia coli k-12 by using a nearby transposon tn10 insertion.a phor strain was constructed with transposon tn10 inserted near the phom+ locus. this was done without any prior knowledge of the phom map location. subsequently, we defined the phom map position by screening tetracycline-sensitive (tcs) derivatives for mutants which were both alkaline phosphatase negative (ther phor phom double mutant phenotype) and auxotrophic simultaneously. some of these mutants were thr-. bacteriophage p1-mediated transductions were used to confirm that phom and its nearby ...19826277871
a site-specific, conservative recombination system carried by bacteriophage p1. mapping the recombinase gene cin and the cross-over sites cix for the inversion of the c segment.the bacteriophage p1 genome carries an invertible c segment consisting of 3-kb unique sequences flanked by 0.6-kb inverted repeats. with insertion and deletion mutants of p1 derivatives the site-specific recombinase gene cin for c inversion) has been mapped adjacent to the c segment and the cix sites (for c inversion cross-over) have been located at the outside ends of the inverted repeats. inversion of the c segment functions as a biological switch and controls expression of the gene(s) respons ...19826327269
cloning of the rho gene of escherichia coli.the map position of the rho gene on e coil chromosome, as determined by phage p1 generalized transduction, was determined. the gene order is ilv-rho-cya. by hind iii endonuclease shotgun technique, the rho+ gene was cloned into a lambda-charon 25 vector. the sizing of the restriction endonuclease generated dna fragments by agarose gel electrophoresis, the heteroduplex analysis of cloned dna molecules by electron microscope and the demonstration of the synthesis of rho protein by the cloned dna s ...19826289052
p1 transduction mapping of the trg locus in rac+ and rac strains of escherichia coli k-12.the trg locus, which had been located at min 31 in the cotransduction gap in the terminus region of the chromosome of escherichia coli, has been mapped by transduction with bacteriophage p1. this locus exhibited no cotransduction with fnr when rac+ strains were used. if rac strains were used, which removed approximately 27 kilobase pairs of dna, trg and fnr exhibited 8.2% cotransduction. although this mapping of trg at min 31.1 considerably reduces the size of the cotransduction gap, trg exhibit ...19826276359
chromosomal location and cloning of the gene (trmd) responsible for the synthesis of trna (m1g) methyltransferase in escherichia coli k-12.the trmd gene, which governs the formation of 1-methyl-guanosine(m1g) in transfer ribonucleic acid (trna), has been located by phage p1 transduction at 56 min on the chromosomal map of escherichia coli. cotransduction to tyra at 56 min is 80%. from the clarke and carbon collection a cole1-tyra+ hybrid plasmid was isolated, which carried the trmd+ gene and was shown to over-produce the trna(m1g)methyltransferase. by subcloning restriction enzyme fragments in vitro, the trmd+ gene was located to a ...19826298573
genetic and biochemical analyses of pantothenate biosynthesis in escherichia coli and salmonella typhimurium.pantothenate (pan) auxotrophs of escherichia coli k-12 and salmonella typhimurium lt2 were characterized by enzymatic and genetic analyses. the panb mutants of both organisms and the pan-6 ("pana") mutant of s. typhimurium are deficient in ketopantoate hydroxymethyltransferase, whereas the panc mutants lack pantothenate synthetase. pand mutants of e. coli k-12 were previously shown to be deficient in aspartate 1-decarboxylase. all mutants showed only a single enzyme defect. the finding that the ...19827037743
suppression of the lexc (ssba) mutation of escherichia coli by a mutant of bacteriophage p1.a new mutant of bacteriophage p1 designated lxc that suppresses the phenotype of lexc and ssba mutants of escherichia coli was isolated and characterized. the properties of lexc mutants suppressed by the lxc mutation include temperature sensitive growth at 42 degrees c, sensitivity to ultraviolet light and alkylating agents, and a nonmutagenic response following exposure to ultraviolet irradiation. a bac mutant of bacteriophage p1 that suppresses the temperature sensitivity of dnab mutants does ...19827050621
phage p1 mutant with decreased abortive transduction. 19827090183
p1 site-specific recombination: nucleotide sequence of the recombining sites.site-specific recombination between molecules of bacteriophage p1 dna occurs at sites called loxp and requires the action of a protein that is the product of the p1 cre gene. although recombination between two loxp sites is very efficient, recombination between loxp and a unique site in the bacterial chromosome (loxb) is inefficient and generates two hybrid lox sites called loxr and loxl. we present here the nucleotide sequences of all four lox sites. analysis of these sequences indicates that ( ...19826954485
genome fusion mediated by the site specific dna inversion system of bacteriophage p1.the genome of bacteriophage p1 contains a segment which is invertible by site specific recombination between sequences near the outside ends of the inverted repeats which flank it. immediately adjacent to this c segment is the coding sequence for cin, the enzyme catalyzing inversion. we show that multicopy plasmids carrying cin and the sequences at which it acts (cix) can form dimers in the absence of the host reca function. further, such plasmids can be cotransduced with p1 markers at high freq ...19836602932
is2 insertion is a major cause of spontaneous mutagenesis of the bacteriophage p1: non-random distribution of target sites.insertion mutations arising spontaneously in the p1 prophage and affecting vegetative phage reproduction were screened for the presence of insertion sequence 2 (is2). filter hybridization identified 28 out of 44 independent insertions as is2. their target specificity is not random. a region that amounts to < 2% of the phage genome had trapped 15 of the 28 is2 elements. however, precise mapping of nine mutants in this hot spot segment revealed no preferred insertion site. rather, the nine is2 are ...198311894911
phosphotransferase-mediated regulation of carbohydrate utilization in escherichia coli k12: location of the gsr (tgs) and iex (crr) genes by specialized transduction.a lysogen of escherichia coli k12 with lambda ci857 s7 xis6 nin5 b515 b519 integrated into ptsi was induced and the lysates plated on a pel- host [on which lambda strains with less than the wild-type amount of dna form plaques at low frequency (cameron et al., 1977)]. all of the 40 plaques examined contained phage able to transduce at least two of the genes known from bacteriophage p1 transduction experiments to be closely linked to ptsi. assuming that each specialized transducing phage arose by ...19836302202
dna restriction--modification genes of phage p1 and plasmid p15b. structure and in vitro transcription.the ecop1 and ecop15 dna restriction-modification systems are coded by the related p1 prophage and p15b plasmid. we have examined the organization of the genes for these systems using p1 itself, "p1-p15" hybrid phages expressing the ecop15 restriction specificity of p15b and cloned restriction fragments derived from these phage dnas. the results of transposon mutagenesis, restriction cleavage analysis. dna heteroduplex analysis and in vitro transcription mapping allow the following conclusions t ...19836302279
dna restriction--modification enzymes of phage p1 and plasmid p15b. subunit functions and structural homologies.we have purified the type iii restriction enzymes ecop1 and ecop15 to homogeneity from bacteria that contain the structural genes for the enzymes cloned on small, multicopy plasmids and which overproduce the enzymes. both of the enzymes contain two different subunits. the molecular weights of the subunits are the same for both enzymes and antibodies prepared against one enzyme cross-react with both subunits of the other. bacteria containing a plasmid derivative in which a large part of one of th ...19836302281
physical analysis of the genomes of hybrid phages between phage p1 and plasmid p15b.the genomes of three plaque-forming recombinant phages between phage p1 and plasmid p15b were characterized by restriction cleavage analysis and electron microscopic heteroduplex studies. the structure of all three p1-15 hybrid genomes differs from that of p1 dna in the res mod region coding for restriction and modification systems ecop15 and ecop1, respectively. p1-15 hybrid 2 shows an additional major difference to p1 around the site of the residential is1 element of p1 and it does not carry a ...19836302282
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