Linkage of polynucleotides through phosphodiester bonds by an enzyme from Escherichia coli.

Abstract

An enzyme purified approximately 600-fold from extracts of E. coli, catalyzes the condensation of short (150 residues) polydeoxythmidylate chains to form deoxythymidylate polymers whose length was increased as much as 20-fold by the formation of typical 3''5[image] phosphodiester linkages. For the reaction to occur, the enzyme requires a divalent cation (Mg++ or Ca++); a factor or factors present in boiled extracts of E. coli; and fixation of the polydeoxythymidylate chains by H2 bonds to a long (3000 residues) deoxyadenylate polymer. The enzyme catalyzes the formation of "covalent circles'' from "H2-bonded circles" of phage X DNA.