The novel P _II -interactor PirC identifies phosphoglycerate mutase as key control point of carbon storage metabolism in cyanobacteria

Significance In this work, we identified the regulatory mechanism of the key control point of cyanobacterial carbon metabolism, the glycolytic phosphoglycerate mutase (PGAM) reaction, converting 3-PGA into 2-PGA and thereby exporting organic carbon from the photosynthetic Calvin cycle. We show that PGAM activity is controlled by a small modulator protein PirC (product of sll0944 ), which inhibits the enzyme through protein–protein interaction....