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

The hyaluronidase gene (hylP) from Streptococcus pyogenes bacteriophage H4489A was previously cloned into Escherichia coli plasmid pUC8 as a 3.1-kilobase ThaI fragment. Southern hybridization experiments confirmed the origin of this fragment in bacteriophage H4489A before determination of the nucleotide sequence of the entire fragment. Two open reading frames (ORFs) were found, the first of which specified a 39,515-molecular-weight protein identified as the bacteriophage hyaluronidase. The second ORF encoded a 65,159-molecular-weight protein of unknown function. Putative transcription and translation control sequences for each ORF were identified by using a plasmid containing a promoterless chloramphenicol acetyltransferase gene. Controlled exclusive expression of the hylP gene via the T7 polymerase-promoter system in E. coli resulted in a 40,000-dalton protein, a result consistent with the coding capacity of the hylP gene.
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PMID:Sequence analysis and expression in Escherichia coli of the hyaluronidase gene of Streptococcus pyogenes bacteriophage H4489A. 264 74

The insect baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV) replicates in insect cell lines in culture. In mammalian cells, however, the virus cannot be propagated. AcNPV DNA does not replicate or persist and is not transcribed in mammalian cells (Tjia et al., 1983). In insect cells productively infected with AcNPV, at least two major late viral gene products have been recognized, the polyhedrin, which makes up the bulk of the polyhedral inclusion bodies in infected cell nuclei, and a 10,000 Da protein (p10) of unknown function. The p10 promoter has been fused to the prokaryotic gene for chloramphenicol acetyltransferase (CAT) as a reporter gene (Knebel et al., 1985). Activity of this construct can be elicited in AcNPV-infected insect cells but not in uninfected insect cells or in mammalian cells. Presumably, the late p10 promoter requires other AcNPV gene products for activity. When the pAcp10-CAT construct is transfected into BHK21 hamster cells at about 18 h after infection with human adenovirus type 5 (Ad5), the insect AcNPV promoter is transactivated in cells of the heterologous mammalian species. The results of S1 protection analyses on the RNA from Ad5-infected and pAcp10-CAT transfected cells reveal that the p10 promoter is used for initiation of transcription. Similarly, the p10 insect virus promoter is activated in BHK21 hamster cells cotransfected with the HindIII-G fragment of adenovirus type 2 (Ad2) DNA which contains the E1A and parts of the E1B region in the left terminal 7.8% of the Ad2 genome. Moreover, in human 293 cells or in BHK297-C131 hamster cells, which both carry and constitutively express the E1 region of Ad5 DNA, the pAcp10-CAT construct is also expressed, and similarly in HE7 hamster cells which carry appreciable portions of the Ad2 genome (Klimkait and Doerfler, 1985). It is concluded that adenovirus functions are capable of transactivating a heterologous insect virus promoter in mammalian cells.
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PMID:Activation of an insect baculovirus promoter in mammalian cells by adenovirus functions. 296 53

Huntington's disease (HD) is a neurodegenerative disorder caused by a (CAG)>37 repeat expansion in a novel gene of unknown function. Although the huntingtin gene is expressed in neuronal and non-neuronal tissues, the disease affects nerve cells of selected regional areas of the central nervous system. To gain insight into the regulation of the HD gene we analysed 1348 bp of the rat huntingtin promoter region. This region lacks a TATA and a CAAT box, is rich in GC content and has several consensus sequences for binding sites for SP1, PEA3, Sif and H2A. The stretch between nucleotides -56 and -206 relative to the first ATG is highly conserved between human and rodents and it harbours several potential binding sites for transcription factors. We analysed deletion mutants fused with the chloramphenicol acetyltransferase reporter gene in transfected, HD-expressing neuronal (NS20Y, NG108-15) and non-neuronal Chinese hamster ovary cell lines. Hence these cells should contain the required trans-acting factors necessary for HD gene expression. Partial deletion of the evolutionarily conserved part of the promoter significantly decreases the activity in both neuronal and non-neuronal cells, indicating that the core promoter activity is located between nucleotides -332 and -15. DNase I footprinting and electrophoretic mobility-shift assays were used to define the nucleotide positions and binding affinity of DNA-protein interactions.
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PMID:Isolation and characterization of the rat huntingtin promoter. 980 5

The location and environment of the acquired blaIMP gene, which encodes the IMP-1 metallo-beta-lactamase, were investigated in a Japanese Pseudomonas aeruginosa clinical isolate (isolate 101/1477) that produced the enzyme. In this isolate, blaIMP was carried on a 36-kb plasmid, and similar to the identical alleles found in Serratia marcescens and Klebsiella pneumoniae clinical isolates, it was located on a mobile gene cassette inserted into an integron. The entire structure of this integron, named In31, was determined. In31 is a class 1 element belonging to the same group of defective transposon derivatives that originated from Tn402-like ancestors such as In0, In2, and In5. The general structure of In31 appeared to be most closely related to that of In5 from pSCH884, suggesting a recent common phylogeny for these two elements. In In31, the blaIMP cassette is the first of an array of five gene cassettes that also includes an aacA4 cassette and three original cassettes that have never been described in other integrons. The novel cassettes carry, respectively, (i) a new chloramphenicol acetyltransferase-encoding allele of the catB family, (ii) a qac allele encoding a new member of the small multidrug resistance family of proteins, and (iii) an open reading frame encoding a protein of unknown function. All the resistance genes carried on cassettes inserted in In31 were found to be functional in decreasing the in vitro susceptibilities of host strains to the corresponding antimicrobial agents.
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PMID:Structure of In31, a blaIMP-containing Pseudomonas aeruginosa integron phyletically related to In5, which carries an unusual array of gene cassettes. 1010 96

The complete primary structure of the str operon of Bacillus stearothermophilus was determined. It was established that the operon is a five-gene transcriptional unit: 5'-ybxF (unknown function; homology to eukaryotic ribosomal protein L30)-rpsL (S12)-rpsG (S7)-fus (elongation factor G [EF-G])-tuf (elongation factor Tu [EF-Tu])-3'. The main operon promoter (strp) was mapped upstream of ybxF, and its strength was compared with the strength of the tuf-specific promoter (tufp) located in the fus-tuf intergenic region. The strength of the tufp region to initiate transcription is about 20-fold higher than that of the strp region, as determined in chloramphenicol acetyltransferase assays. Deletion mapping experiments revealed that the different strengths of the promoters are the consequence of a combined effect of oppositely acting cis elements, identified upstream of strp (an inhibitory region) and tufp (a stimulatory A/T-rich block). Our results suggest that the oppositely adjusted core promoters significantly contribute to the differential expression of the str operon genes, as monitored by the expression of EF-Tu and EF-G.
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PMID:Cloning and characterization of the str operon and elongation factor Tu expression in Bacillus stearothermophilus. 1102 32

The genetic basis of neurodegeneration in Huntington's disease (HD) has been identified as a (CAG)(>37) repeat expansion in a gene of unknown function. Interestingly, patients with the same expanded (CAG)(n) repeat length may have markedly different ages at onset. Based on experiences in animal models the level of expression might be one of the modifying factors. To gain insight into the regulation of the human HD gene we functionally analyzed 2266 bp of the HD gene promoter region. This region lacks a TATA and a CAAT box, is GCrich, and it has several consensus sequences for SP1, AP-2 and AP-4 binding sites. The stretch between nucleotides -49 and -198 relative to the first ATG is highly conserved between human and rodents and it harbors several potential binding sites for transcription factors. We analyzed deletion mutants fused with the chloramphenicol acetyltransferase (CAT) reporter gene in transfected, huntingtin expressing neuronal (NS20Y) and non-neuronal (CHO) cell lines. Partial deletion of the evolutionarily conserved part of the promoter significantly reduces the activity in both neuronal and non-neuronal cells indicating that the core promoter activity is located between nucleotides -221 and 4, relative to the +1 translation start site. Binding affinities of DNA-protein interactions were defined by electrophoretic mobility shift assays and the protected nucleotide positions were determined by DNase I footprinting.
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PMID:Functional characterization of the human Huntington's disease gene promoter. 1148 45

Highly reduced E. coli strains, MDS40, MDS41, and MDS42, lacking approximately 15% of the genome, were grown to high cell densities to test their ability to produce a recombinant protein with high yields. These strains lack all transposons and insertion sequences, cryptic prophage and many genes of unknown function. In addition to improving genetic stability, these deletions may reduce the biosynthetic requirements of the cell potentially allowing more efficient production of recombinant protein. Basic growth parameters and the ability of the strains to produce chloramphenicol acetyltransferase (CAT) under high cell density, batch cultivation were assessed. Although growth rate and recombinant protein production of the reduced genome strains are comparable to the parental MG1655 strain, the reduced genome strains were found to accumulate significant amounts of acetate in the medium at the expense of additional biomass. A number of hypotheses were examined to explain the accumulation of acetate, including oxygen limitation, carbon flux imbalance, and metabolic activity of the recombinant protein. Use of a non-catalytic CAT variant identified the recombinant protein activity as the source of this phenomenon; implications for the metabolic efficiency of the reduced genome strains are discussed.
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PMID:Expression of two recombinant chloramphenicol acetyltransferase variants in highly reduced genome Escherichia coli strains. 1749 38