Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The tellurite resistance (Ter) determinant of the IncP alpha plasmid RK2Ter, a variant of RK2 (also called RP4), is located between the kilA and korA genes involved in plasmid replication control. Transcriptional and translational fusions were constructed between the gene for beta-galactosidase and the kilA and Ter genes by using the transpositional phage mini-Mu. These fusions indicated that the Ter genes are transcribed in the same direction as kilA and that transcription and translation of the cloned kilA gene are occurring and may not be lethal to the bacterial cell even in the absence of korA. The nucleotide sequence of this region was determined, and three open reading frames (ORFs) were identified. The first ORF codes for KilA, a 28-kDa hydrophilic protein. The second ORF, telA, codes for a hydrophilic protein of 42 kDa. The third ORF, telB, codes for a hydrophobic protein of 32 kDa. This protein appears to be located in the inner membrane of the bacterial cell, since fusions of TelB to alkaline phosphatase were obtained by using TnphoA. All three proteins were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after overproduction using the T7 RNA polymerase/promoter system. The same three proteins were produced when Tes and Ter derivatives of RP4 were expressed in an in vitro transcription-translation system. A single Ser-to-Cys missense mutation in telB was found to be responsible for mutation of RK2 to Ter.
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PMID:Transcriptional analysis, translational analysis, and sequence of the kilA-tellurite resistance region of plasmid RK2Ter. 184 56

Two major subspecies of Staphylococcus cohnii, namely S. cohnii subsp. cohnii, from humans, and S. cohnii subsp. urealyticum, from humans and other primates, are described on the basis of a study of 14 to 25 strains and 18 to 33 strains, respectively. DNA-DNA hybridization studies conducted in our laboratory in 1983 (W. E. Kloos and J. F. Wolfshohl, Curr. Microbiol. 8:115-121, 1983) demonstrated that strains representing the different subspecies were significantly divergent. S. cohnii subsp. urealyticum can be distinguished from S. cohnii subsp. cohnii on the basis of its greater colony size; pigmentation; positive urease, beta-glucuronidase, and beta-galactosidase activities; delayed alkaline phosphatase activity; ability to produce acid aerobically from alpha-lactose; and fatty acid profile. The type strain of S. cohnii subsp. cohnii is ATCC 29974, the designated type strain of S. cohnii Schleifer and Kloos 1975b, 55. The type strain of S. cohnii subsp. urealyticum is ATCC 49330.
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PMID:Staphylococcus cohnii subspecies: Staphylococcus cohnii subsp. cohnii subsp. nov. and Staphylococcus cohnii subsp. urealyticum subsp. nov. 185 41

The lsp gene of Escherichia coli encodes the inner membrane enzyme, signal peptidase II (SPase II). SPase II is comprised of 164 amino acid residues and contains four hydrophobic domains. A series of lsp-phoA and lsp-lacZ gene fusions have been constructed in vitro to determine the topology of SPase II. The fusion junction for each of these gene fusions was determined by DNA sequencing. The lengths of the SPase II fragment in the fusions varied from 12 to 159 amino acid residues. Strains containing SPase II-PhoA fusions to the two predicted periplasmic loops exhibited higher levels of alkaline phosphatase activity than fusions to the predicted cytoplasmic domains. In contrast, SPase II-LacZ fusions at the cytoplasmic and the periplasmic domains of SPase II showed high and low levels of beta-galactosidase activity, respectively, a result opposite to those shown by SPase II-PhoA fusions located at precisely the same amino acid of SPase II. Taken together, these results strongly support the predicted model for SPase II topology, i.e. this enzyme spans the cytoplasmic membrane four times with both the amino and the carboxyl termini facing the cytoplasm.
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PMID:Membrane topology of Escherichia coli prolipoprotein signal peptidase (signal peptidase II). 189 46

To determine the variability in test results obtained with the Escherichia coli PQ37 genotoxicity assay (SOS chromotest) when varying the test protocol, we examined the influences of sodium dodecylsulfate (SDS) concentrations, of buffer pH and composition on the enzyme assays, the effects of E. coli PQ37 density and culture conditions on the expression and/or determination of alkaline phosphatase (ap) and beta-galactosidase (beta-g) activities, the calculated induction factors (IF) and the SOS-inducing potentials (SOSIP). Initially, we used 0-190 ng (0-1 nmole) 4-nitroquinoline-1-oxide (4-NQO) as a reference compound for the standard procedure in the absence of metabolic activation. Subsequently, to evaluate the results of protocol variations we examined several mutagenic compounds of differing chemical classes using both the standard and a modified assay procedure. We observed the highest enzyme activities using 1 mg SDS per tube and calibrating the ap buffer to pH 8.05 and the beta-g buffer to pH 7.75. The longer the incubation period, the higher the enzyme activities. However, with respect to IF and SOSIP there is no reason to incubate in excess of 90 min. We found no significant differences in the IF and SOSIP values when varying substrate conversion times. There was, however, a definite decrease in beta-g activity when extended substrate incubation times were used. Higher enzyme activities are obtained when the bacterial count is increased. Using lower bacterial counts the enzyme activities decreased, but the sensitivity of E. coli towards genotoxic compounds increased.
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PMID:Sources of variability of the Escherichia coli PQ37 genotoxicity assay (SOS chromotest). 189 12

Three different histochemical marker genes--E. coli beta-galactosidase gene (lacZ), Drosophila alcohol dehydrogenase gene (ADH) and human placenta alkaline phosphatase gene (ALP)--were cloned into a eukaryotic expression vector also containing the neomycin resistance gene. After calcium phosphate transfection and G418 sulfate selection of recipient BALB/c 3T3 cells, stable transfectants were pooled for histochemical staining. The lacZ-bearing cells produce aqua blue staining for beta-galactosidase; ADH-bearing cells, blue-black staining for alcohol dehydrogenase; and ALP-bearing cells, red staining for alkaline phosphatase. Cells carrying different marker genes can be easily differentiated by double-staining protocols. In addition, various photographic films can be used to enhance the colors of specific histochemically tagged cell classes. These plasmid vectors, providing selectability with the neomycin resistance gene and ultrasensitivity of alternative histochemical marker genes, will be very effective in virtually any biological system requiring analyses of multiple cell clones or classes in culture model systems or in situ.
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PMID:Selectable plasmid vectors with alternative and ultrasensitive histochemical marker genes. 193 Oct 36

The MalF protein is an integral membrane protein of Escherichia coli containing eight membrane-spanning stretches and a large periplasmic domain of approximately 180 amino acids. We have asked whether this protein is dependent for its membrane insertion on the bacterial secretion machinery specified by the sec genes. Using azide to inhibit the SecA protein and sec mutants to reduce the functioning of the machinery, we have studied the membrane assembly of MalF and beta-galactosidase and alkaline phosphatase fusions to MalF. In no case did we see an effect of reducing sec gene function on the insertion of MalF or fusion proteins. Selection for mutants that would cause internalization of a MalF-beta-galactosidase hybrid protein yielded no mutations in sec genes. Our results suggest that MalF can assemble in the membrane independently of the bacterial secretion machinery.
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PMID:Membrane insertion of the Escherichia coli MalF protein in cells with impaired secretion machinery. 193 36

The PHO8 gene of Saccharomyces cerevisiae encodes repressible alkaline phosphatase (rALPase; EC 3.1.3.1). The rALPase activity of the cells is two to three times higher in medium containing a low concentration of Pi than in high-Pi medium due to transcription of PHO8. The Pi signals are conveyed to PHO8 by binding of PHO4 protein, a positive regulatory factor, to a promoter region of PHO8 (PHO8p) under the influence of the PHO regulatory circuit. Deletion analysis of PHO8p DNA revealed two separate regulatory regions required for derepression of rALPase located at nucleotide positions -704 to -661 (distal region) and -548 to -502 (proximal region) and an inhibitory region located at -421 to -289 relative to the translation initiation codon. Gel retardation experiments showed that a beta-galactosidase-PHO4 fusion protein binds to a 132-bp PHO8p fragment bearing the proximal region but not to a 226-bp PHO8 DNA bearing the distal region. The fusion protein also binds to a synthetic oligonucleotide having the same 12-bp nucleotide sequence as the PHO8p DNA from positions -536 to -525. The 132-bp PHO8p fragment, connected at position -281 of the 5' upstream region of a HIS5'-'lacZ fused gene, could sense Pi signals in vivo, but a 20-bp synthetic oligonucleotide having the same sequence from -544 to -525 of the PHO8p DNA could not. Linker insertions in the PHO8p DNA indicated that the 5-bp sequence 5'-CACGT-3' from positions -535 to -531 is essential for binding the beta-galactosidase-PHO4 fusion protein and for derepression of rALPase.
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PMID:Specific cis-acting sequence for PHO8 expression interacts with PHO4 protein, a positive regulatory factor, in Saccharomyces cerevisiae. 199 Feb 83

After incubation at 37 degrees C in the absence of Ca2+ ions, pathogenic strains of Yersinia spp. release large amounts of a set of plasmid-encoded proteins called Yops. The secretion of these proteins, involved in pathogenicity, occurs via a mechanism that involves neither the removal of a signal sequence nor the recognition of a C-terminal domain. Analysis of deletion mutants allowed the secretion recognition domain to be localized within the 48 N-terminal amino acids of protein YopH, within the 98 N-terminal residues of protein YopE, and within the 76 N-terminal residues of YopQ. Comparison of these regions failed to reveal any sequence similarity, suggesting that the secretion signal of Yop proteins is conformational rather than sequential. Hybrid proteins containing the amino-terminal part of YopH fused to either the alpha-peptide of beta-galactosidase or to alkaline phosphatase deprived of its signal sequence were efficiently secreted to the Yersinia culture medium. This observation opens new prospects in using Yersinia spp. as chimeric-protein producers and as potential live carriers for foreign antigens.
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PMID:Secretion of hybrid proteins by the Yersinia Yop export system. 199 87

A prospective study was performed in the Dutch flower bulb culture to investigate the possible effects of subchronic exposure to the soil fumigant 1,3-dichloropropene (DCP) on liver and kidney function and on glutathione conjugation capacity in blood. Urine spot samples and venous blood samples from 14 workers applying DCP (applicators) were taken at the start of the season in July, and after the season in October. The parameters of liver function measured were: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyltranspeptidase, and total bilirubin (conjugated and unconjugated). Total bilirubin was significantly decreased from 9.5 before to 7.0 mumol/l after the season. In combination with an increase in serum gamma-glutamyltranspeptidase activity from 12.5 to 19.5 U/l this indicates moderate hepatic enzyme induction. To study renal function, creatinine and beta 2-microglobulin in serum, and beta 2-microglobulin, albumin, alanine aminopeptidase, beta-galactosidase, and retinol binding protein in urine were measured. The glomerular function parameters albumin in urine and creatinine in serum changed significantly during the season: albumin concentration increased from 5.2 to 7.6 mg/l, whereas creatinine concentration [corrected] decreased from 93.0 to 87.5 mumol/l. The tubular function parameter retinol binding protein also increased in concentration from 20.0 to 26.9 micrograms/l. Therefore, a subclinical nephrotoxic effect of subchronic exposure to DCP cannot be excluded. Effects on glutathione conjugation capacity were studied by measuring erythrocyte glutathione S-transferase activity and blood glutathione concentrations. The activity of glutathione S-transferase in erythrocytes was significantly decreased from 4.7 before to 3.3 U/g haemoglobin after the season. The same was true for the blood glutathione concentrations, which decreased from 0.93 to 0.82 mM.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Biological effect monitoring of occupational exposure to 1,3-dichloropropene: effects on liver and renal function and on glutathione conjugation. 191 9

We have constructed a series of broad-host-range plasmids which use "visual screens" to detect promoter activity. These plasmids contain the pMB1 and pRO1600 origins of replication and are capable of replicating in a wide range of gram-negative bacteria. The genes encoding beta-galactosidase and alkaline phosphatase from Escherichia coli and bacterial luciferase from Vibrio harveyi supply the promoterless indicator genes. The constructs were tested in E. coli and Pseudomonas aeruginosa.
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PMID:Construction of broad-host-range plasmid vectors for easy visible selection and analysis of promoters. 211 10


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