Project description:Lantibiotics are ribosomally synthesized antimicrobial peptides with substantial posttranslational modifications. They are characterized by the unique amino acids lanthionine and methyllanthionine, which are introduced by dehydration of Ser/Thr residues and linkage of the resulting dehydrated amino acids with Cys residues. BLAST searches using the mersacidin biosynthetic enzyme (MrsM) in the NCBI database revealed a new class II lantibiotic gene cluster in Bacillus pseudomycoides DSM 12442. Production of an antimicrobial substance with activity against Gram-positive bacteria was detectable in a cell wash extract of this strain. The substance was partially purified, and mass spectrometric analysis predicted a peptide of 2,786 Da in the active fraction. In order to characterize the putative lantibiotic further, heterologous expression of the predicted biosynthetic genes was performed in Escherichia coli. Coexpression of the prepeptide (PseA) along with the corresponding modification enzyme (PseM) resulted in the production of a modified peptide with the corresponding mass, carrying four out of eight possible dehydrations and supporting the presence of four thioether and one disulfide bridge. After the proteolytic removal of the leader, the core peptide exhibited antimicrobial activity. In conclusion, pseudomycoicidin is a novel lantibiotic with antimicrobial activity that was heterologously produced in E. coli.
Project description:The aim of the experiments was to determine the regulon of the Bacillus subtilis alternative sigma factor SigI. Biological relevance: To expand our knowledge about Bacillus subtilis transcriptional network under unfavorable conditions. Experimental workflow overview: Bacillus subtilis 168 trp+ (BaSysBio) was used as the genetic background. (i) sigI-rsgI knock-out, (ii) rsgI knock-out, and (iii) wr strains were cultured in LB medium to mid-exponential phase at 37°C and 52°C. Total RNA was isolated from 3 ml of the culture. rRNA was depleted from the samples with RiboMinus; subsequently RNA-seq libraries were prepared (Illumina compatible NEXTflex Rapid Directional RNA-Seq Kit, Bioo Scientific) and sequenced at the EMBL GeneCore facility. The experiment was performed in three independent replicates.
Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes.
Project description:This series represents the work described in the publication Bacillus subtilis Genome Diversity by Earl et al. (Journal of Bacteriology, accepted) Keywords: comparative genomic hybridization
