Enzymic synthesis of polynucleotides. I. Polynucleotide phosphorylase of azotobacter vinelandii.

The isolation, partial purification and some properties of polynucleotide phosphorylase of Azotobacter vinelandii are described. The enzyme catalyzes the synthesis of highly polymerized ribonucleic acid-like polynucleotides from 5′-nucleoside diphosphates with release of orthophosphate. The reaction requires magnesium ions and is reversible. Thus, the enzyme also catalyzes the phosphorolysis of polynucleotides to yield the corresponding 5′-nucleoside diphosphates. The preparation and isolation of a number of polynucleotides containing one or several kinds of mononucleotide units is described. The scope, mechanism and significance of the reaction are discussed.