Role of small proteins and the moonlighting enzyme GapA in the degradosome-like network of Bacillus subtilis

• Applicant: Privatdozentin Dr. Sabine Brantl
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 492739895

B. subtilis is the most important non-pathogenic Gram-positive model organism. It is naturally competent, can sporulate to survive extreme conditions and secrete proteins in large quantities. Only five small proteins, among them SR1P and SR7P, have been investigated in some detail. In B. subtilis, a degradosome-like protein network (DLN) has been proposed that involves the RNases Y, J1/J2, PnpA, helicase CshA and as scaffolding components the metabolic enzymes enolase and PfkA. Our group has added to this network first data on GapA as further scaffolding component and two small proteins, SR1P and SR7P. The major aims of this application are to investigate the global role of both SR1P and SR7P on the B. subtilis degradosome-like protein network (DLN) under defined metabolic and stress conditions and to further elucidate the interaction network and biological role of GapA in the B. subtilis DLN. The experimental work will be divided into the following parts, which will be approached in parallel1) Identification of all RNase Y substrates that are affected by SR7P and all RNase J substrates that are affected by SR1P under defined stress conditions (in collaboration with Ulrike Mäder, University Greifswald) and analysis of the physiological role of the small proteins in regulatory networks involving these substrates2) Investigation of the role of GapA in the DLN and of a potential effect of SR1P on Gap-bound RNase Y and on PnpA in B. subtilis3) Mapping of the enolase/RNase Y and SR7P/enolase interaction surfaces4) Investigation of a potential concerted action of SR1/SR1P or SR7/SR7P in the sam pathway

• DFG Programme: Research Grants