Glucosamine-P and rhodococcal ADP-glucose pyrophosphorylases: A hint to (re)discover (actino)bacterial amino sugar metabolism

Biochimie. 2020 Sep:176:158-161. doi: 10.1016/j.biochi.2020.07.006. Epub 2020 Jul 21.


Glycogen was described as a temporal storage molecule in rhodococci, interconnecting lipids and carbon availability. The Rhodococcus jostii ADP-glucose pyrophosphorylase (ADP-GlcPPase) kinetic and regulatory properties support this role. Curiously, the enzyme uses glucosamine-1P as alternative substrate. Herein, we report the in-depth study of glucosamine-1P activity and its regulation in two rhodocoocal ADP-GlcPPases, finding that glucosamine-6P (representing a metabolic carbon/nitrogen node) is a critical activator, then reinforcing the role of glycogen as an "intermediary metabolite" in rhodococci. Glucosamine-1P activity in rhodococcal ADP-GlcPPases responds to activation by metabolites improving their catalytic performance, strongly suggesting its metabolic feasibility. This work supports a scenario for new molecules/metabolites discovery and hypothesizes on evolutionary mechanisms underlying enzyme promiscuity opening novel metabolic features in (actino)bacteria.

Keywords: Allosterism; Glucosamine-1P; Glucosamine-6P; Glycogen; Triacyclglycerol.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Glucosamine / biosynthesis*
  • Glucose-1-Phosphate Adenylyltransferase / metabolism*
  • Rhodococcus / metabolism*


  • Bacterial Proteins
  • Glucose-1-Phosphate Adenylyltransferase
  • Glucosamine

Supplementary concepts

  • Rhodococcus jostii