1,721,045 research outputs found
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
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
The molecular function of SwrA: an auxiliary factor modulating DegU transcriptional activity
No full textWe recently demonstrated that the main fla/che promoter PA(fla/che) can be bound by the phosphorylated form of DegU (DegU~P) with two opposite outcomes: complete repression if DegU~P alone is bound to PA(fla/che) DNA; transcriptional stimulation if DNA is bound by DegU~P complexed with SwrA.
Thus SwrA, which is necessary for swarming motility, constitutes an auxiliary factor that modulates the transcriptional activity of the response regulator DegU turning it from a repressor into an activator of PA(fla/che). Evidences indicate that SwrA might modulate other DegU~P-regulated promoters.
Also, we demonstrated that DegU32(Hy) is a mutant protein unable to functionally interact with SwrA at the fla/che promoter; the phenotype of degU32(Hy) strains differs from that of the wild type DegU~P and we suggest the use of degS200(Hy) mutant strains for studies aimed at analyzing the effect of the level of DegU phosphorylation.
SwrA is coded by a gene containing a slippery poly-adenine tract that allows phase variations between a functional and a non-functional allelic state.
In swrA+ cells (typically in undomesticated strains) fla/che transcription oscillates from the basal/medium level to the activated state that is required for swarming. When swrA is in the non-functional form (e.g. in the 168 laboratory strain) fla/che transcription can oscillate between a repressed state in which no flagella are made and a basal/medium level of transcription sufficient for a limited swimming motility. While in both swrA- and swrA+ strains oscillations depend on phosphorylation of DegU mediated by environmental stimuli, in swrA- cells the secondary fla/che promoter PD3(fla/che) plays an important role that might constitute the bistable switch acting on motility
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
The UP element of the promoter for the flagellin gene,hag,stimulates transcription from both SigD-and SigA-dependent promoters in Bacillus subtilis.
No full textDNA sequences upstream (UP element) of the core promoter (-10, -35 region) of the Bacillus subtilis flagellin gene hag stimulate transcription in vivo and in vitro. We constructed a number of hybrids, placing the UP element of hagp upstream of the core of one SigD-dependent (fliDp) and two SigA-dependent (tmsp, vegp) B. subtilis promoters. The hybrid promoters were fused to a lacZ reporter gene and their activity tested in vivo. The presence of the UP module enhanced transcription at both types of promoters. We conclude that the hagp UP sequence can act as a promoter module independently of the core sequence
CAP 16A Screening for motility.
No full textBook with a description of the genes, functions, methods used in the course of the EU-Japanese project for the systematic functional analysys of the Bacillus genome that followed its genome sequencing
CAP.16 Genes affecting motility
No full textBook with a description of the genes, functions, methods used in the course of the EU-Japanese project for the systematic functional analysys of the Bacillus genome that followed its genome sequencing
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