Reversible synthesis of polyribonucleotides with an enzyme from Escherichia coli.

Studies on nucleotide and coenzyme synthesis in this laboratory led to an attempt to convert nucleoside 5’-polyphosphates to polyribonucleotides. We were able to show that extracts of Escherichia coli convert C14-adenine-labeled ATP1 to an acid-insoluble nucleotide, and that the addition of adenylate kinase increased the rate of the reaction (1, 2). The discovery of Ochoa and coworkers ( 3 , 4) that polyribonucleotides are formed from nucleoside diphosphates in a reaction catalyzed by an enzyme from Azotobacter vinelandii made it clear that ADP rather than ATP was the reactive component. In preliminary reports ( 1 , 2) we have described briefly an enzyme from E’. coli which converts nucleoside diphosphates to polynucleot,ides according to thc following general equation : n nucleoside-PP d (nucleoside-P), + nP,