Paul Hudson | New metabolite regulation of the bacterial Calvin cycle revealed by proteomics

Paul Hudson - KTH Royal Institute of Technology, Sweden
Homepage: www.hudsonlab.se/
Twitter: / paulsimv
New metabolite regulation of the bacterial Calvin cycle revealed by interaction proteomics
Metabolite-level regulation of enzyme activity allows microbes to quickly regulate metabolic pathways during environmental shifts. This same regulation can complicate metabolic engineering strategies, as pathway flux becomes less sensitive to enzyme overexpression. Our knowledge of such regulations is limited for most microbial strains. Here I will describe our work using chemoproteomics methods to identify metabolite-protein interactions in the proteomes of cyanobacteria as well as litho-autotrophic bacteria that fix CO2 using the Calvin cycle. We have screened over 25 metabolites in the cyanobacteria proteome. Clustering analysis of the hundreds of detected interactions showed that some metabolites interacted in a species-specific manner, such as interactions of glucose-6-phosphate in Cupriavidus necator and of glyoxylate in Synechocystis sp. PCC 6803. Some metabolite-enzyme interactions were also tested for effects on catalytic activity, such as those to the fructose-1,6/sedoheptulose-1,7-bisphosphatase (F/SBPase). Of particular interest was the Calvin cycle intermediate GAP, which activated both Synechocystis and Cupriavidus F/SBPase in reducing conditions, which suggests a feed-forward activation of the Calvin cycle in both photoautotrophs and chemolithoautotrophs. I will discuss the implications of these findings for metabolic engineering in these strains.
This talk is part of the CyanoWorld online seminar series, hosted by Nicolas Schmelling, and was held on Zoom on March 9th, 2023.
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