Project description:Comparative genome analysis revealed seven uncharacterized genes, sven0909 to sven0915, adjacent to the previously identified chloramphenicol biosynthetic gene cluster (sven0916-sven0928) of Streptomyces venezuelae strain ATCC 10712 that was absent in a closely related Streptomyces strain that does not produce chloramphenicol. Transcriptional analysis suggested that three of these genes might be involved in chloramphenicol production, a prediction confirmed by the construction of deletion mutants. These three genes encode a cluster-associated transcriptional activator (Sven0913), a phosphopantetheinyl transferase (Sven0914), and a Na(+)/H(+) antiporter (Sven0915). Bioinformatic analysis also revealed the presence of a previously undetected gene, sven0925, embedded within the chloramphenicol biosynthetic gene cluster that appears to encode an acyl carrier protein, bringing the number of new genes likely to be involved in chloramphenicol production to four. Microarray experiments and synteny comparisons also suggest that sven0929 is part of the biosynthetic gene cluster. This has allowed us to propose an updated and revised version of the chloramphenicol biosynthetic pathway.
Project description:BldC is a transcriptional regulator essential for morphological development Streptomyces venezuelae. Although bldC deletion strain is unable to produce aerial hyphae, electron microscopy reveals that almost all of the colony biomass is in the form of spores rather than undifferentiated vegetative hyphae. This ChIP-chip experiment was carried out to determine the binding sites, and thence the regulon, of BldC in Streptomyces venezuelae. Cy3(IP):Cy5(Total) signal ratios in the wild type were compared to those in a bldC knockout strain.
Project description:WhiA is an unusual transcriptional regulator found in Streptomyces species related to eukaryotic homing endonucleases. It plays a central role in sporulation in these bacteria. The aim of this transcription profiling experiment was to measure genome wide transcript levels in the wild type and the whiA deletion mutant at 7 time points from 8 to 20 hours during the growth cycle of Streptomyces venezuelae.
Project description:WhiH is a transcription factor found in Streptomyces species. It has a role in sporulation in these bacteria. Although mutants in whiH are able to form aerial mycelia, these fail to differentiate into spores. The aim of this transcription profiling experiment was to measure genome wide transcript levels in the wild type and the whiH deletion mutant at 7 time points from 8 to 20 hours during the growth cycle of Streptomyces venezuelae.
Project description:WhiG is a sigma factor found in Streptomyces species. It has a central role in sporulation in these bacteria. Although mutants in whiG are able to form aerial mycelia, these fail to differentiate into spores. The aim of this transcription profiling experiment was to measure genome wide transcript levels in the wild type and the whiG deletion mutant at 7 time points from 8 to 20 hours during the growth cycle of Streptomyces venezuelae.
Project description:The sporulating, filamentous soil bacterium Streptomyces venezuelae ATCC 10712 differentiates under submerged and surface growth conditions. In order to lay a solid foundation for the study of development-associated division for this organism, a congenic set of mutants was isolated, individually deleted for a gene encoding either a cytoplasmic (i.e. ftsZ) or core inner membrane (i.e. divIC, ftsL, ftsI, ftsQ, ftsW) component of the divisome. While ftsZ mutants are completely blocked for division, single mutants in the other core divisome genes resulted in partial, yet similar, blocks in sporulation septum formation. Double and triple mutants for core divisome membrane components displayed phenotypes that were similar to those of the single mutants, demonstrating that the phenotypes were not synergistic. Division in this organism is still partially functional without multiple core divisome proteins, suggesting that perhaps other unknown lineage-specific proteins perform redundant functions. In addition, by isolating an ftsZ2p mutant with an altered -10 region, the conserved developmentally controlled promoter was also shown to be required for sporulation-associated division. Finally, microscopic observation of FtsZ-YFP dynamics in the different mutant backgrounds led to the conclusion that the initial assembly of regular Z rings does not per se require the tested divisome membrane proteins, but the stability of Z rings is dependent on the divisome membrane components tested. The observation is consistent with the interpretation that Z ring instability likely results from and further contributes to the observed defects in sporulation septation in mutants lacking core divisome proteins.
Project description:The whiH gene is required for the differentiation of aerial hyphae into spores in Streptomyces species. It is a predicted member of the GntR family of transcription factors and has been shown to bind specifically to a sequence in its own promoter. This ChIP-Seq experiment was carried out to determine all the binding sites whiH binds to in the genome of Streptomyces venezuelae. A whiH deletion strain was made and a FLAG tagged whiH protein was expressed in it from a genome-integrated plasmid. Then anti-FLAG antibodies were used for chromatin immunoprecipitation followed by high throughput sequencing. The wild type Streptomyces venezuelae strain (ATCC 10712) was used as a negative control. For both the FLAG-WhiH strain and the WT strain, non-immunoprecipitated (total) DNA was also sequenced to arrive at a background enrichment which could be subtracted from the enrichment in the immunoprecipated sample.
Project description:WhiB is the founding member of a family of proteins (the WhiB-like [Wbl] family) that carry a [4Fe-4S] iron-sulfur cluster and play key roles in diverse aspects of the biology of actinomycetes, including pathogenesis, antibiotic resistance, and the control of development. In Streptomyces, WhiB is essential for the process of developmentally controlled cell division that leads to sporulation. The aim of this transcription profiling experiment was to measure genome wide transcript levels in the wild type and the whiB deletion mutant at 7 time points from 8 to 20 hours during the growth cycle of Streptomyces venezuelae.
