The beta-d-galactosidase of Escherichia coli, strain K-12.
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منابع مشابه
Possible mechanisms underlying the slow lactose fermentation phenotype in Shigella spp.
A Southern hybridization analysis revealed that the region homologous to Escherichia coli lacZ was present on the chromosomal DNAs of beta-galactosidase-positive Shigella strains, such as Shigella dysenteriae serovar 1 and Shigella sonnei strains, whereas this region was absent from chromosomal DNAs of beta-galactosidase-negative strains of Shigella flexneri and Shigella boydii. We found that t...
متن کاملDerepression of beta-galactosidase synthesis in Escherichia coli K-12 by p-fluorophenylalanine.
p-Fluorophenylalanine (FPA) derepresses beta-galactosidase synthesis at 35 C but not at 25 C in Escherichia coli K-12, strain MC132 (lac I1,2), a strain with a temperature-sensitive lac repressor. In contrast, strain MC130 (lac I(+)) is not derepressed by FPA at 35 C. Temperature-shift experiments with strain MC132 in the presence of FPA and other reagents (isopropyl-1-thio-beta-d-galactoside o...
متن کاملDecay of ribonucleic acid synthesis in amino acid-starved Escherichia coli after rifampin treatment.
The concentration of rifampin necessary to affect the initiation of ribonucleic acid (RNA) synthesis quickly in Escherichia coli strains K-12 and 15TAU was about 200 mug/ml, as determined by extrapolation of the effect of the drug on the induction of beta-galactosidase synthesis. A lag in the action of rifampin of about 10 s was confirmed. Rifampin was then used as a probe to compare RNA synthe...
متن کاملRegulation of argA operon expression in Escherichia coli K-12: cell-free synthesis of beta-galactosidase under argA control.
Regulation of argA operon expression in Escherichia coli K-12 was studied in a cell-free, deoxyribonucleic acid-dependent, enzyme-synthesizing system. lambdaAZ-7 deoxyribonucleic acid, which carries a fusion of the lacZ structural gene to the argA operon so that beta-galactosidase synthesis is under argA regulation, was used as the template. To eliminate extraneous readthrough from lambda promo...
متن کاملD-Allose catabolism of Escherichia coli: involvement of alsI and regulation of als regulon expression by allose and ribose.
Genes involved in allose utilization of Escherichia coli K-12 are organized in at least two operons, alsRBACE and alsI, located next to each other on the chromosome but divergently transcribed. Mutants defective in alsI (allose 6-phosphate isomerase gene) and alsE (allulose 6-phosphate epimerase gene) were Als(-). Transcription of the two allose operons, measured as beta-galactosidase activity ...
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عنوان ژورنال:
- Journal of bacteriology
دوره 60 4 شماره
صفحات -
تاریخ انتشار 1950