Identification of two poly (A) Polymerases in Bacillus subtilis

Two poly(A) polymerase activities were identified in extracts of a strain of Bacillus subtilis in which the gene for polynucleotide phosphorylase was disrupted. Gel filtration studies showed a large difference in the molecular size of the two poly(A) polymerases. On the other hand, the two enzymes resembled the two major poly(A) polymerases of Escherichia coli both with respect to size and in many of their catalytic properties. The observation that both B. subtilis and E. coli have two poly(A) polymerases with many common properties suggest interesting parallels in the processing of the 3′‐ends of mRNA in gram‐positive and gram‐negative bacteria.