Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The genes of Yersinia enterocolitica serotype O:3 (YeO3) that determine the synthesis of the O-side-chain of the lipopolysaccharide, the rfb region, were cloned into plasmid pBR322. The O-side-chain of YeO3 was expressed by the clone both in Escherichia coli and Salmonella typhimurium indicating that the entire rfb region was included in the clone. It was shown by restriction mapping, deletion analysis and transposition mutagenesis that about 10.4 kilobase pairs of DNA was essential for the synthesis and expression of the O-side-chain. The correct assembly of the O-side-chain on the cell surface of the clone was confirmed by immunofluorescence microscopy and slide agglutination. Immunoblotting using monoclonal antibody specific for the O-side-chain of YeO3 revealed that the O-side-chain material synthesized by the clone in E. coli was similar to that of YeO3. The clone did not show the in vitro temperature variation in O-side-chain expression characteristic of YeO3. Instead analogous O-side-chain was produced both at 25 degrees C and at 37 degrees C. Using transposon Tn2507, which carries a promotorless chloramphenicol acetyltransferase (CAT) gene, transcriptional fusions with the target DNA were generated. When testing the ability of mutated clones to produce CAT, transcription was shown to occur in a uniform direction throughout the whole rfb region. In colony hybridizations, using the cloned insert as a probe, homologous DNA was detected only in pathogenic Y. enterocolitica serotypes.
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PMID:Expression cloning of Yersinia enterocolitica O:3 rfb gene cluster in Escherichia coli K12. 185 98

The delivery of DNA to target cells using simple, defined, nonviral systems has become an area of intense interest in gene therapy. We describe here the development and characterization of one such novel system. A recombinant, bifunctional, fusion protein was expressed and purified from Escherichia coli. This protein consists of the DNA-binding domain of the yeast transcription factor GAL4 fused to the cell binding, internalization domain of the Yersinia pseudotuberculosis inv gene product, invasin. This protein, GAL4/Inv, together with poly-L-lysine, formed complexes with a chloramphenicol acetyltransferase (CAT) reporter plasmid that contains eight repeats of the GAL4 consensus recognition sequence. These complexes were shown to transfect target cells in an invasin receptor-dependent manner, resulting in transient CAT expression. A simple, targeted DNA delivery vehicle, as we describe here, represents a viable approach to nonviral gene delivery.
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PMID:Gene transfer using a novel fusion protein, GAL4/invasin. 921 42

The antibiotic-multiresistance IncF plasmid pRSB107 was isolated by a transformation-based approach from activated-sludge bacteria of a wastewater-treatment plant. It confers resistance to ampicillin, penicillin G, chloramphenicol, erythromycin, kanamycin, neomycin, streptomycin, sulfonamides, tetracycline and trimethoprim and against mercuric ions. Complete sequencing of this plasmid revealed that it is 120 592 bp in size and has a G+C content of 53.1 mol%. The plasmid backbone is composed of three replicons, RepFIA, RepFIB and RepFII, which are almost identical to corresponding regions located on the F-plasmid and on R100. The three replicons encode replication initiation (rep) and replication control, multimer resolution (mrs), post-segregational killing of plasmid-free cells (psk) and active plasmid partitioning (sopABC locus). Part of the F-leading region and remnants of the F-homologous DNA-transfer (tra) module complete the pRSB107 backbone. Plasmid pRSB107 contains a complex, highly mosaic 35 991 bp antibiotic-resistance region consisting of a Tn21- and a Tn10-derivative and a chloramphenicol-resistance module. The Tn21 derivative is composed of a mercury-resistance region (mer), a Tn4352B-like kanamycin/neomycin-resistance transposon, a streptomycin/sulfonamide-resistance module, remnants of the beta-lactam-resistance transposon Tn1, a macrolide-resistance module flanked by copies of IS26 and IS6100, remnants of Tn402 integrating a class 1 integron and the Tn21-specific transposition module. A truncated version of the tetracycline-resistance transposon Tn10 and the chloramphenicol acetyltransferase gene catA complete the pRSB107 resistance region. In addition to antibiotic resistance, pRSB107 encodes the following putative virulence-associated functions: (i) an aerobactin iron-acquisition siderophore system (iuc/iut); (ii) a putative high-affinity Fe(2+) uptake system which was previously identified on a pathogenicity island of Yersinia pestis and in the genome of the phytopathogen Erwinia carotovora subsp. atroseptica SCRI1043; (iii) an sn-glycerol-3-phosphate transport system (ugp); and (iv) the virulence-associated genes vagCD having a possible function in stable plasmid inheritance. All the accessory modules are framed by insertion sequences, indicating that pRSB107 was gradually assembled by integration of different horizontally acquired DNA segments via transposition or homologous recombination.
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PMID:The 120 592 bp IncF plasmid pRSB107 isolated from a sewage-treatment plant encodes nine different antibiotic-resistance determinants, two iron-acquisition systems and other putative virulence-associated functions. 1581 78