1,721,067 research outputs found
The sequence of the trp operon of Bacillus subtilis 168 (trpC2) revisited.
No full textThe origin of the 168 strain of Bacillus subtilis based on the comparison of its trp operon sequnce with that of other WT strain
Mutant of Bacillus subtilis with temperature sensitive lesion in ribonucleic acid synthesis during germination.
Full text linkWe have isolated a mutant of Baccillus subtilis with a temperature-sensitive lesion in the process of spore germination. The temperature-sensitive mutation affects only germination and outgrowth, and the earliest defect observed is an early block of ribonucleic acid synthesis during germination at 46 C. Upon return to 35 C there is a complete repair of the impaired function, even in the absence of protein synthesis. Protein synthesis inhibition during germination of the mutant spores at 46 C has the effect of increasing the amount of ribonucleic acid made. The temperature-sensitive mutation is located near aroI
Geni e genomi: sequenza completa del genoma del batterio B. subtilis.
No full textTecnologie cromosomiche in Bacillus a seguito del sequenziamento dell'intero genoma.Ricadute biotecnologich
Pattern of RNA transcription during Bacillus subtilis spore outgrowth.
No full textDuring the outgrowth of Bacillus subtilis spores, there is a period of RNA and protein synthesis in the absence of DNA replication. Two mutants of B. subtilis, PB2442 (gsp-4) and PB2452 (gsp-81), were used to study the pattern of RNA synthesis during this period. The two mutants are temperature-sensitive in the outgrowth phase, and show a limited amount of incorporation of (3H)uridine at 47 degrees C. The RNAs synthesized during a 2 min pulse with (3H)uridine were hybridized to EcoRI-digested DNA, after agarose gel electrophoresis and transfer to nitrocellulose paper (Southern technique). For both mutants the transcripts synthesized at 35 degrees C at different times were different. Differences were also observed in the transcripts made at 47 degrees C. For both mutants, in the presence of chloramphenicol, the same hybridization pattern was obtained for RNAs pulse-labelled at different periods during outgrowth
The Bacillus subtilis outB gene is highly homologous to an Escherichia coli ntr-like gene.
No full textThe Bacillus subtilis outB gene was found to have strong similarities to an Escherichia coli gene complementing ntr-like mutations in Rhodobacter capsulatus. The deduced gene products had 52% identical amino acids (65% similar residues). The phenotype of strains affected in the OutB function indicates that this B. subtilis gene may be involved in nitrogen utilization
Amplification of a chromosomal region in Bacillus subtilis.
No full textWe report on the amplification in Bacillus subtilis of a defined DNA sequence after exposure of the bacteria to increasing levels of antibiotic. The experimental system consisted of transformation of competent cells with a plasmid (pRHA39) unable to replicate in the host and carrying the alpha-amylase gene derived from B. subtilis. Selection of transformants resistant to 5 micrograms of chloramphenicol per ml resulted in the isolation of strains with the plasmid integrated into the chromosome at the site of homology, by a Campbell type mechanism. Starting from such a nontandem duplication, amplification was achieved by growing the bacteria in increasing concentrations of chloramphenicol. By dilution, Southern blotting, and hybridization to a radioactive probe, we estimated a copy number of about 10 for the amplified sequence of samples grown in the presence of 50 micrograms of chloramphenicol per ml. No free plasmid could be detected in the amplified strains. The extent of the amplified region was the same for all transformants, and the endpoints appeared to be the same in all isolates. As a consequence of the amplification, there was a noticeable increase in amylase production, and the amount of enzyme produced correlated with gene dosage. The amplification did not occur in a recE genetic background
Functional analysis of the Bacillus subtilis yshD gene, a mutS paralogue
No full textIn the course of the Bacillus subtilis genome sequencing project, an ORF called yshD was identified, and its product was classified as a mismatch repair protein. Further analysis of the YshD primary sequence showed that the protein belongs to the MutS2 protein family, sharing a high degree of identity with the Thermootoga Inaritima protein TM1278 (34%) and with the so-called MutS2 protein sl11772 of Synechocystis (32%). The COG1193 family of MutS-like proteins is made up of polypeptides that have been predicted from genomic sequencing data from various prokaryotes, but their biological role has not yet been analysed. The functional study of yshD revealed that the gene is constitutively transcribed during the life cycle of B. subtilis, and in minimal medium expression remains at appreciable levels until very late in stationary phase. Fluctuation tests with yshD knock-out mutants did not indicate any role for the protein in preventing the accumulation of spontaneous forward mutations to RifR, nor was any functional interaction with MutS or MutL suggested in fluctuation experiments with mutants lacking combinations of the three genes. Nevertheless, the mutation spectrum observed in the rpoB gene in the deltayshD strain has some characteristic features. The gene does not seem to be involved in the prevention of interspecific recombination in transformation-competent cells
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