Some Evolutionary Relationships of the Primary Biological Catalysts Glutamine Synthetase and RuBisCO

The polypeptide folds of two primary biological catalysts have been determined by X-ray crystallography. One is glutamine synthetase (GS) from Salmonella typhimurium, which catalyzes the entry of nitrogen into metabolism, and the other is ribulose bisphosphate carboxylase/oxygenase (RuBisCO) from tobacco, which catalyzes the entry of carbon into metabolism. Both are oligomeric structures having complicated patterns of interdomain and intersubunit contacts.