0000000000667270
AUTHOR
Paola Salerno
Artificial chromosome libraries of Streptomyces coelicolor A3(2) and Planobispora rosea
Using an Escherichia coli-Streptomyces shuttle vector derived from a bacterial artificial chromosome (BAC), we developed methodologies for the construction of BAC libraries of filamentous actinomycetes. Libraries of Streptomyces coelicolor, the model actinomycete, and Planobispora rosea, a genetically intractable strain, were constructed. Both libraries have an average insert size of 60 kb, with maximal insert larger than 150 kb. The S. coelicolor library was evaluated by selected hybridisations to DraI fragments and by end sequencing of a few clones. Hybridisation of the P. rosea library to selected probes indicates a good representation of the P. rosea genome and that the library can be u…
The Streptomyces coelicolor dnaK operon contains a second promoter driving the expression of the negative regulator hspR at physiological temperature
HspR (heat shock protein regulator) acts as a negative regulator of different genes in many bacteria. In Streptomyces coelicolor hspR gene is part and the transcriptional repressor of the dnaK operon which encodes the DnaK, GrpE, DnaJ chaperone machines and HspR itself. Our experiments led us to the discovery of a second promoter, internal to dnaK operon, located upstream hspR gene. Transcription from this promoter was detected at 30 degrees C indicating that hspR could play a key physiological role.