Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Bacteriol ; 171(2): 1228-32, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2492510

RESUMO

The genes that encode the two subunits of Bacillus subtilis phenylalanyl-tRNA synthetase were cloned from alpha lambda library of chromosomal B. subtilis DNA by specific complementation of a thermosensitive Escherichia coli pheS mutation. Both genes (we named them pheS and pheT, analogous to the corresponding genes of E. coli) are carried by a 6.6-kilobase-pair PstI fragment which also complements E. coli pheT mutations. This fragment directs the synthesis of two proteins identical in size to the purified alpha and beta subunits of the phenylalanyl-tRNA synthetase of B. subtilis with Mrs of 42,000 and 97,000, respectively. A recombinant shuttle plasmid carrying the genes caused 10-fold overproduction of functional phenylalanyl-tRNA synthetase in B. subtilis.


Assuntos
Aminoacil-tRNA Sintetases/genética , Bacillus subtilis/genética , Clonagem Molecular , Escherichia coli/genética , Genes Bacterianos , Genes , Fenilalanina-tRNA Ligase/genética , Bacillus subtilis/enzimologia , Genótipo , Substâncias Macromoleculares , Mutação , Fenótipo , Fenilalanina-tRNA Ligase/biossíntese , Mapeamento por Restrição
2.
Appl Environ Microbiol ; 52(5): 1046-54, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2431653

RESUMO

At a concentration of 10 micrograms/ml, patulin caused single-strand DNA breaks in living cells of Escherichia coli. At 50 micrograms/ml, double-strand breaks were observed also. Single-strand breaks were repaired in the presence of 10 micrograms of patulin per ml within 90 min when the cells were incubated at 37 degrees C in M9-salts solution without a carbon source. The same concentration also induced temperature-sensitive lambda prophage and a prophage of Bacillus megaterium. When an in vitro system with permeabilized Escherichia coli cells was used, patulin at 10 micrograms/ml induced DNA repair synthesis and inhibited DNA replication. The in vivo occurrence of DNA strand breaks and DNA repair correlated with the in vitro induction of repair synthesis. In vitro the RNA synthesis was less affected, and overall protein synthesis was not inhibited at 10 micrograms/ml. Only at higher concentrations (250 to 500 micrograms/ml) was inhibition of in vitro protein synthesis observed. Thus, patulin must be regarded as a mycotoxin with selective DNA-damaging activity.


Assuntos
Dano ao DNA , DNA Bacteriano/efeitos dos fármacos , Escherichia coli/genética , Patulina/farmacologia , Piranos/farmacologia , Bacteriófago lambda , Centrifugação com Gradiente de Concentração , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA Bacteriano/biossíntese , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Cinética , Lisogenia , RNA Bacteriano/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...