Nucleoside diphosphokinase of Salmonella typhimurium.

Nucleoside diphosphokinase from Salmonella typhimurium has been purified and characterized. In many respects, the enzyme is similar to those from higher organisms in that it has a broad speciCcity for both phosphate donor and recipient and that it functions via a ping-pong mechanism. The enzyme activity of cells is very high at all growth rates but decreases as growth rate increases. Evidence is presented that nucleoside diphosphokinase is sufficient to account for the synthesis of all nucleoside triphosphates required for the polymerization of nucleic acids and that it is probably the only enzyme that catalyzes the synthesis of triphosphates from diphosphates and the y-phosphate of ATP.