Physical Sciences and Mathematics Commons^™

Unraveling The Activation Mechanism Of The Potato Tuber Adp-Glucose Pyrophosphorylase, Carlos M. Figueroa, Misty L. Kuhn, Christine A. Falaschetti, Ligin Solamen, Kenneth W. Olsen, Miguel Ballicora, Alberto A. Iglesias

Chemistry: Faculty Publications and Other Works

ADP-glucose pyrophosphorylase regulates the synthesis of glycogen in bacteria and of starch in plants. The enzyme from plants is mainly activated by 3-phosphoglycerate and is a heterotetramer comprising two small and two large subunits. Here, we found that two highly conserved residues are critical for triggering the activation of the potato tuber ADP-glucose pyrophosphorylase, as shown by site-directed mutagenesis. Mutations in the small subunit, which bears the catalytic function in this potato tuber form, had a more dramatic effect on disrupting the allosteric activation than those introduced in the large subunit, which is mainly modulatory. Our results strongly agree with …