Concerted transcriptional and post-transcriptional control of Bacillus Phytase gene by the regulator proteins PhoP, AbrB, and CcpA

• Antragsteller: Professor Dr. Rainer Borriss
• Fachliche Zuordnung: Stoffwechselphysiologie, Biochemie und Genetik der Mikroorganismen
• Förderung: Förderung von 2008 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 66598390

According to our previous results, the phytase gene of Bacillus is regulated by three different regulators in different manner: 1) The superordinate, positive transcriptional regulation is directed by the response regulator PhoP. However, higher concentrations of PhoP cause a decrease of transcription efficiency suggesting a fine tuned regulatory mechanism of PhoP on phyC-promoter. 2) The negative control of the transcription is accomplished by the global regulator AbrB. This protein binds in a homo-tetrameric form to the upstream and downstream region simultaneously thereby impeding the RNA-polymerase on transcription. 3) The third regulator is the key protein of catabolite repression CcpA. It is affecting the phyC-expression in a positive manner, however the mechanism is still not understood. Within the last year we made some progress in refining the molecular mechanisms of these regulators on phyC expression. We published our results The results of our investigations concerning the AbrB interactions with phyC have been published in 2008 and a second paper describing the kinetic parameters of the interaction is now submitted. In 2008 as an anti-repressor of AbrB, named AbbA, was detected, we have been started to analyse the binding properties of this protein as well. The work is well progressing and we plan to publish more of our recent results in course of the next year.

• DFG-Verfahren: Sachbeihilfen