Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A composite plasmid (pAT2010) has been constructed in vitro from RSF2124 and Bacillus subtilis IFO3022 plasmid (pAT1060) by covalent joining of the two DNA molecules by means of Escherichia coli DNA ligase through the cohesive ends generated by restriction endonuclease RI (EcoRI) cleavage. The composite plasmid was selected by transformation of E. coliC600r-m- with the ligated mixture after enrichment for composite plasmid by preparative agarose gel electrophoresis, and plating of the transformants on a medium containing ampicillin and colicin E1. Treatment of the composite plasmid with EcoRI yielded two fragments corresponding to the linear forms of the parental plasmids. The composite plasmids replicated as biologically functionally units in E. coli, and expressed genetic information carried by RSF2124. In the presence of chloramphenicol, the composite plasmids continued to replicate and the copy number gradually increased. Such nature of replication in the presence of chloramphenicol is characteristic to RSF2124 derived from colicin E1 factor, and so it is suggested that the replicator of RSF2124 is functional in the composite plasmid. The composite plasmid was found to synthesize mRNA of B. subtilis plasmid in cell-free extracts of E. Coli, by hybridization of the mRNA to the original plasmid DNA of pAT1060.
Mol Gen Genet 1977 Nov 29
PMID:Molecular cloning and in vitro transcription of Bacillus subtilis plasmid in Escherichia coli. 41 72

The properties of two plasmids coding for the CcoRI restriction and modification enzymes are described. Both plasmids are non auto-transferring (NTP) but can be mobilised by transfer factors. Strains carrying NTP13 produce colicin E1 and the EcoRI enzymes. This plasmid has a molecular weight of 6 X 10(6) daltons and is present as approximately 12 copies per chromosome. The second plasmid, NTP14, was detected after mobilisation of the EcoRI plasmid with the R factor RI-19. NTP14 codes for ampicillin resistance, synthesis of the EcoRI enzymes and colicin E1. The molecular weight of NTP14 is 10.7 X 10(6) daltons and there are about 14 copies per chromosome. DNA-DNA reassociation experiments were performed to determine the interrelationships of NTP13, NTP14, ColE1 and the R factor R1-19. NTP13 and NTP14 continue to replicate when cellular protein synthesis is inhibited by the addition of chloramphenicol.
Mol Gen Genet 1976 Feb 02
PMID:Characterisation of plasmids coding for the restriction endonuclease EcoRI. 76 64

An investigation of in vitro mutagenesis of plasmid DNA with hydroxylamine is described. The treated plasmid DNA was used to transform Escherichia coli K12. Mutants of the plasmid NTP3, which codes for resistance to ampicillin and sulphonamides, were isolated and characterised. They were classified according to the reduction in level of their beta-lactamase activity. Hydroxylamine-induced mutants of NTP14 were also isolated. This plasmid codes for ampicillin resistance, synthesis of colicin E1, and the EcoRI restriction and modification enzymes. One class of mutants is lethal to the host strain at temperatures above 33 degrees C, but carrier strains grow well at 28 degrees C. There is evidence that these mutants code for a temperature-sensitive EcoRI modification activity: the lethal effect probably results from the cleavage of the host-cell DNA by the restriction enzyme at non-permissive temperatures. The possible genetic uses of the mutant plasmids for the production of hybrid plasmids in the bacterial cell are discussed.
Mol Gen Genet 1976 Apr 23
PMID:Mutagenesis of plasmid DNA with hydroxylamine: isolation of mutants of multi-copy plasmids. 77 4

A 3.2 Mdal sequence of DNA, TnA, which contains the ampicillin (Ap) resistance determinant has been translocated from an R plasmid to the plasmid ColE1. A total of 12 isolates were studied. There are at least 8 sites in ColE1 at which TnA has inserted. Insertion at five of these has resulted in a Col-phenotype. One ColE1-Apr plasmid, RSF2124, was examined further and its replication properties are found to be similar to that of the parent plasmid. RSF2124 appears to be a useful plasmid vehicle for the molecular cloning of DNA from diverse prokaryotic sources: it codes for readily detectable Ap resistance and contains a single EcoRI site in a gene affecting colicin biosynthesis so that it is unable to produce colicin upon ligation to other DNA.
Mol Gen Genet 1975 Dec 30
PMID:The generation of a ColE1-Apr cloning vehicle which allows detection of inserted DNA. 104 10

In pBR329, the genes providing resistance to ampicillin (beta-lactamase, bla) and chloramphenicol (chloramphenicol acetyl transferase, cat) are encoded on the same strand. The bla gene lies downstream of the cat gene, separated by an intergenic sequence of 414 bp. The transcription starts of the two genes are 1090 bp apart. We have probed, in vivo, the effect on transcription of the bla gene, of the introduction, in front of the cat gene, of a series of synthetic promoters covering a large (over 60-fold) range of efficiency. The rising efficiency of the cat promoter has several important consequences for transcription of the bla gene. First, a strong (up to sevenfold) stimulation of the bla promoter is observed, together with a shift of the main bla transcription start site, 10 bp upstream. Furthermore, the relative efficiencies of the bla transcription terminators are reduced. Finally, because of a lesser relative efficiency of the cat transcription terminators as well, we observe enhanced intrusion into the bla gene of transcripts initiated at the cat promoter, some of them extending to the bla transcription terminator and beyond. The operon-like expression of the cat-bla gene tandem is controlled by the efficiency of the cat terminator, which in turn depends on that of the cat promoter. This demonstrates a direct link between the efficiencies of promoter and terminator. Upon inhibition of bacterial gyrase activity, i.e. relaxation of negative supercoiling action, bla expression increases sharply in pBR329, but remains almost unchanged in a plasmid (pBRGC-1) in which cat is under the control of a 6.5-fold stronger promoter. Therefore, under normal gyrase activity, the stimulation of the bla promoter in pBRGC-1 (relative to pBR329) appears to be linked to topological relaxation of its template in situ, in keeping with earlier in vitro observations. We propose that the relaxed state of pBRGC-1 in situ could be due to the decrease in the plasmid linking number, introduced by the 10-12 RNA polymerases that simultaneously transcribe the cat gene in that plasmid, compared with only one or two in pBR329. We find that the negative superhelical densities of both plasmids are almost identical when extracted from the cell. Therefore gyrase would not correct for the relaxed state of plasmid pBRGC-1 observed in situ.
Mol Microbiol 1992 Jun
PMID:In vivo control of promoter and terminator efficiencies at a distance. 132 24

Plasmid pSI30 was constructed to increase the sensitivity of detection of a genetically engineered micro-organism (GEM) and its recombinant DNA in environmental samples. This broad host-range, mobilizable plasmid contained chlorocatechol (clc) degradative genes, antibiotic resistance genes (ampicillin and kanamycin) and a fragment of eukaryotic DNA. The clc genes encode enzymes that convert 3-chlorocatechol to maleylacetic acid permitting the host, Pseudomonas putida RC-4, to grow on 3-chlorobenzoate. This catabolic phenotype was exploited using enrichment procedures to detect RC-4(pSI30) cells, free-living in the water column or when irreversibly bound to surfaces. The eukaryotic DNA sequence provided a unique target allowing positive identification by DNA:DNA hybridization. Using the eukaryotic DNA sequence as a probe, no transfer of the plasmid to indigenous bacteria was detected. Persistence of RC-4(pSI30) and its ability to multiply upon addition of 3-chlorobenzoate were demonstrated 78 days after its addition to natural freshwater. In flow-through microcosms RC-4(pSI30), undetectable as free-living cells, was found by enrichment as irreversibly bound sessile forms. These experiments revealed the stability of pSI30 and its utility in a 'combination' detection system for tracking the survival of a GEM and its DNA in environmental samples.
Mol Ecol 1992 Oct
PMID:Use of a novel plasmid to monitor the fate of a genetically engineered Pseudomonas putida strain. 134 90

A plasmid vector (denoted pRC2312) was constructed, which replicates autonomously in Escherichia coli, Saccharomyces cerevisiae and Candida albicans. It contains LEU2, URA3 and an autonomously replicating sequence (ARS) from C. albicans for selection and replication in yeasts, and bla (ampicillin resistance) and ori for selection and replication in E. coli. S. cerevisiae AH22 (Leu-) was transformed by pRC2312 to Leu+ at a frequency of 1.41 x 10(5) colonies per microgram DNA. Transformation of C. albicans SGY-243 (Ura-) to Ura+ with pRC2312 resulted in smaller transformant colonies at a frequency of 5.42 x 10(3) per microgram DNA where the plasmid replicated autonomously in transformed cells, and larger transformant colonies at a frequency of 32 per microgram DNA, in which plasmid integrated into the genome. Plasmid copy number in yeasts was determined by a DNA hybridization method and was estimated to be 15 +/- 3 per haploid genome in S. cerevisiae and 2-3 per genome in C. albicans replicative transformants. Multiple tandem integration occurred in integrative transformants and copy number of the integrated sequence was estimated to be 7-12 per diploid genome. The C. albicans ADE2 gene was ligated into plasmid pRC2312 and the construct transformed Ade- strains of both C. albicans and S. cerevisiae to Ade+. The vector pRC2312 was also used to clone a fragment of C. albicans genomic DNA containing an aspartic proteinase gene. C. albicans transformants harboring this plasmid showed a two-fold increase in aspartic proteinase activity. However S. cerevisiae transformants showed no such increase in proteinase activity, suggesting the gene was not expressed in S. cerevisiae.
Mol Gen Genet 1992 Nov
PMID:Cloning and expression of Candida albicans ADE2 and proteinase genes on a replicative plasmid in C. albicans and in Saccharomyces cerevisiae. 146 16

Electrotransformation of Rhodococcus fascians by non-replicating plasmids containing a suitable resistance marker resulted in stable transformants by integration of these constructs at various sites in the genome, thereby generating different mutations. Tagged genes could be isolated in Escherichia coli owing to the presence of a CoIE1 replicon and an ampicillin resistance gene in the inserted sequences. Southern analysis and nucleotide sequencing revealed that recombination can occur at defined locations in the plasmid, while no site preference for target sequences could be detected. Low homology between the recombining sequences indicates illegitimate recombination. The specificity of the plasmid sites could be explained by assuming a linear recombination intermediate, generated by cleavage of the transformed plasmid.
Mol Microbiol 1991 Sep
PMID:Illegitimate integration of non-replicative vectors in the genome of Rhodococcus fascians upon electrotransformation as an insertional mutagenesis system. 166 59

Much of the literature on penicillin hypersensitivity is devoted to the identification of penicillin antigens rather than allergens. Human IgE-binding determinants on different penicillins have rarely been closely investigated with the view of defining fine structural allergenic features and differences. We have developed radioimmunoassays employing ampicillin, amoxicillin and ticarcillin solid phases for the detection of penicillin-reactive IgE antibodies. Quantitative hapten inhibition studies employed to identify IgE-binding regions on the penicillin molecules revealed a heterogeneous group of allergenic determinants consisting exclusively, or in part, of the alpha-aminobenzyl and benzyl side chain groups and the beta-lactam and thiazolidine rings of the penicillin nucleus.
Mol Immunol 1990 Nov
PMID:Identification of penicillin allergenic determinants that bind IgE antibodies in the sera of subjects with penicillin allergy. 170 Oct 26

Synthetic probes complementary to ribosomal RNA are increasingly used in the detection of bacteria. Many applications, however, require the quantitation of bacteria. We therefore tested the influence of growth phase and representative antibiotics (ampicillin, chloramphenicol and gentamycin) on the outcome of DNA/RNA filter hybridization using radiolabelled probes and a multisample digital autoradiograph for quantitative monitoring. Hybridization efficiency seemed influenced by the binding capacity of the membrane, availability of target molecules and physiological growth control. For chloramphenicol the absolute hybridization signal remained constant over the experimental period. Only a slight decrease was found in experiments with gentamycin whereas viable counts dropped 10,000-fold. For ampicillin a decrease in viable counts was paralleled by diminishing signal strengths. Relative signal strengths (counts per viable cell) increased in all experiments with antibiotics. In conclusion; (i) RNA probes seem to detect bacteria even after onset of antimicrobial therapy; (ii) DNA/RNA filter hybridization appears not suitable for accurate quantitation of bacteria.
Mol Cell Probes 1990 Oct
PMID:Effects of growth phase and antibiotics on quantitative DNA/RNA hybridization. 170 4


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>