RESUMO
Here, we report the cloning of a 5.8-kb PstI fragment of chromosomal DNA from Bacillus stearothermophilus (Bt) carrying the three genes, grpE, dnaK and dnaJ. This fragment contains, in addition, the 3'-end of an open reading frame which has been shown to be part of the dnaK operon in three bacterial species. The dnaJ gene could complement an Escherichia coli dnaJts mutant for growth at high temperature. Sequencing and hybridization data strongly suggest that the Bt chromosome contains an analog of dnaJ.
Assuntos
Proteínas de Bactérias/genética , DNA Bacteriano/genética , Proteínas de Escherichia coli , Geobacillus stearothermophilus/genética , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico/genética , Óperon/genética , Sequência de Aminoácidos , Sequência de Bases , Cromossomos Bacterianos/genética , Clonagem Molecular , Teste de Complementação Genética , Proteínas de Choque Térmico HSP40 , Dados de Sequência Molecular , Fases de Leitura AbertaRESUMO
The size of poly (A)-RNA from polysomes and cell nuclei of the yeast Saccharomyces cerevisiae was investigated. Pulslabelled cells ([14C] adenin) were cracked by the French press; polysomes and nuclei were separately isolated and the RNA was finally extracted with phenol. The separation of poly (A)-containing and poly (A)-lacking fractions was achieved by oligo (dT) cellulose. These fractions were characterized by sedimentation analysis. The main portion of polysomal poly (A)-RNA sedimented with a rate of 8 to 14S, whereas the poly (A)-RNA of nuclei exhibited a sedimentation rate of 12 to 17S. Thus nuclear poly (A)-RNA is about 20-30% larger than polysomal poly (A)-RNA.