dna element of corynebacterium diphtheriae with properties of an insertion sequence and usefulness for epidemiological studies.the segment of dna which is inserted within the tox gene of bacteriophage gamma and is responsible for its tox- phenotype was found to be present and repeated approximately 30 times in the chromosome of corynebacterium diphtheriae belfanti 1030. other c. diphtheriae strains contained a variable number of copies (1 to 25) of the same element. sequence analysis showed that this repeated and interspersed dna element was flanked by 9-base-pair direct repeats and that the 5' and 3' ends of the insert ...19873025175
pcr-based tandem epitope tagging system for escherichia coli genome engineering.biological discovery in the postgenomic era requires a systematic and high-throughput experimental approach. to this end, a versatile pcr-based tandem epitope tagging system is described, which inserts a tandem epitope coding sequence into any desired position of the escherichia coli chromosome. template plasmids were constructed that carry tandem copies of the epitope encoding sequence, flp recombinase target (frt) sites, and antibiotic resistance genes. the linear dna fragment, amplified from ...200616454042
generation and pcr screening of bacteriophage gamma sublibraries enriched for rare clones (the "sublibrary method"). 19979031159
dnab125, a dnab nonsense mutation.a temperature-sensitive dnab mutation, dnab125, was shown to be a suppressed amber mutation. the effects of inserting different amino acids at the mutated site via amber suppressors were examined for both escherichia coli and bacteriophage gamma growth. in addition, the dnab125 amber allele was shown to be different from the previously described dnab amber allele, dnab266. the extent of residual deoxyribonucleic acid synthesis observed in a supf(ts) dnab125 strain at high temperature revealed th ...19816263858
nucleotide sequence and transcription of a rat trna(phe) gene and a neighboring alu-like element.a bacteriophage gamma ch4a clone containing a 22-kb rat dna insert was isolated and found to contain a solitary trna(phe)gaa gene and, 436 bp downstream of it, an alu-like element. the nucleotide sequence of a 1141-bp dna fragment containing these genes was determined. the rat trna(phe)gaa gene, with the exception of an additional a in the extra arm, has a sequence identical to that of a rabbit liver trna(phe). the alu-like element belongs to the rodent b2 family of short interspersed repetitive ...19883234768
chain length determination of small double- and single-stranded dna molecules by polyacrylamide gel electrophoresis.we describe the use of polyacrylamide gel electrophoresis to estimate chain lengths of double- and single-stranded dna molecules in the size range 20-1000 base pairs (or nucleotides). double-stranded dna molecules of known length produced either by organic synthesis or by restriction endonuclease digestion of viral dnas were used as standards. the relative electrophoretic mobilities of these standards were examined on both nondenaturing (aqueous) polyacrylamide gels and on denaturing gels contai ...19751174504
attempts to purify a membrane attached chromoid of bacteriophage lambda.using methods which proved successful for the isolation of e. coli chromosome in a folded form (the e. coli chromoid), we have attempted to purity the "native" form of bacteriophage gamma chromosome from gamma infected cells. upon sedimentation of lysates we find that phage dna separates into two fractions, one of which cosediments with the bacterial chromoid ; the other sediments nearer to the top of gradient. both fractions probably contain membrane-bound phage dna, and both support the in viv ...1976779853
restriction insensitivity in bacteriophage t5 i. genetic characterization of mutants sensitive to ecori restriction.unmodified bacteriophage t5 is able to grow normally on bacterial hosts carrying three different escherichia coli restriction systems, ecok, ecopi, and ecori. under the same conditions, the plating efficiency of bacteriophage gamma is less than 10(-9). at least in the case of ecori, this lack of in vivo restriction is not due to lack of restriction sites on the t5 dna molecule. these observations suggest that bacteriophage t5 specifies one or more restriction protection systems. mutants (ris) of ...1979430589
plasmid replication and hfr formation in strains of escherichia coli carrying seg mutations.several conditional-lethal mutantions that do not permit the replication of f-factors of escherichia coli k-12 are located at a site called seg. this gene is located on the e. coli chromosome between ser b and thr. it is unrelated to other known genes involved in dna replication. strains carrying seg mutations were unable to replicate f'-lac+, several f'-gal+s, f'-his+ and bacteriophage gamma at 42 degrees. however, neither phage t4, cole1, nor any of the r factors tested were prevented from rep ...1977320453
the gamma protein specified by bacteriophage gamma. structure and inhibitory activity for the recbc enzyme of escherichia coli.the protein encoded by the gam gene of bacteriophage lambda ("gamma protein") is a specific inhibitor of the recbc enzyme of escherichia coli. the lambda protein has been purified approximately 2,000-fold, and its structure and inhibitory activity have been characterized. it appears to be composed of two identical subunits of 16,500 daltons, inhibits all of the catalytic activities of the recbc enzyme with apparently equal efficiency, but has no effect upon any other e. coli or lambda-dnase test ...1975126236
alternatively spliced mrnas code for different polypeptide chains of the chicken neural cell adhesion molecule (n-cam).rabbit polyclonal antibodies directed against the chicken neural cell adhesion molecule (n-cam) were used to isolate four overlapping cdna clones from a chicken cdna expression library in bacteriophage gamma gt11. these clones collectively accounted for 3.8 kilobases of n-cam mrna sequence and hybridized specifically to two 6-7-kilobase brain polyadenylated rna species that co-migrated with previously identified n-cam mrnas. dna fragments derived from an internal region of the cloned cdna sequen ...19863001098
nucleotide sequence of the bovine gene for follicle-stimulating hormone beta-subunit.the gene for the beta-subunit of follicle-stimulating hormone (fsh-beta) was isolated from a library of bovine dna fragments cloned in bacteriophage gamma and the complete nucleotide sequence of the gene was determined. the bovine fsh-beta gene contains approximately 4000 nucleotides and consists of three exons separated by two intervening sequences. the transcription initiation site of the gene was mapped by nuclease protection experiments. analysis of rna species present in pituitary mrna demo ...19882840246
polyamine biosynthesis in escherichia coli: construction of polyamine-deficient mutants.previous work is summarized on the biosynthetic pathway for polyamines in escherichia coli. deletion mutants have been obtained in the various biosynthetic steps, resulting in cells with no polyamines. these mutants grow at one-third the rate of polyamine-supplemented cultures and can serve as suitable hosts for bacteriophages t4, t7, q beta, and f2. the major effects of polyamine deficiency in these polyamine-deficient strains are: (i) these cells do not serve as hosts for bacteriophage gamma a ...19817040834
double-strand breaks on artificial chromosomes in yeast.yeast artificial chromosomes composed primarily of bacteriophage gamma dna exhibit very low levels of meiotic crossing over compared with similarly sized intervals of natural yeast dna. when these recombinationally quiet chromosomes were augmented with a 12.5 kb insert of sequences from yeast chromosome viii, genetic studies demonstrated that the artificial chromosomes had acquired recombination properties characteristic of this region of chromosome viii. on authentic yeast chromosomes, most mei ...200010968251
[adsorption processes in viruses. ii. recording of adsorption isotherms and estimation of the influence of ph value of the t3-bacteriophage-gamma-aluminium oxide system]. 195713434366
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