Sofia Doello

Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis. Theyhad and have tremendous influence on the biogeochemical cycles on Earth. Recently,cyanobacteria are increasingly investigated as cell factories for a sustainableeconomy. Despite their global, environmental and rising economic importance, ourknowledge on the regulation of their primary metabolism is fragmented.Cyanobacteria switch between photoautotrophic and heterotrophic modes ofmetabolism during day/night cycles or ...

Glucose-6-phosphate dehydrogenase (G6PDH), the enzyme that catalyzes the first step of the oxidative pentose phosphate (OPP) pathway, plays a key role in this process. G6PDH is produced at the onset of nitrogen starvation but remains inactive in dormant cells, only to be rapidly reactivated when nitrogen is restored. In this study, we investigated the mechanisms underlying this enzymatic regulation and found that G6PDH inactivation is primarily due to the accumulation of inhibitory metabolites. ...

Analysis of the sequences of PGM1 from several Synechocystis strains revealed a different annotation for Synechocystis sp. PCC 6803, which included a 16-amino acid N-terminal extension that is missing in the other strains. Additionally, the experimentally validated transcriptional start site from Synechocystis sp. PCC 6803 suggests a shorter open reading frame for PGM1, with Met 17 as putative translational start site. To clarify if the N-terminal extension is an annotation error, we prepared ...

To test the effecf of phosphorylation of Ser 47 on PGM1 activity, this residue was exchanged for Ala and Asp and the activity of the recombinant proteins was measured in vitro.