TheStreptomyces coelicolorPolynucleotide PhosphorylaseHomologue, and Not the Putative Poly(A) Polymerase, CanPolyadenylateRNA

Abstract
A protein containing a nucleotidyltransferase motif characteristic of poly(A) polymerases has been proposed to polyadenylate RNA inStreptomyces coelicolor(P. Bralley and G. H. Jones, Mol. Microbiol.40:1155-1164, 2001). We show that this protein lacks poly(A) polymerase activity and is instead a tRNA nucleotidyltransferase that repairs CCA ends of tRNAs. In contrast, aStreptomyces coelicolorpolynucleotide phosphorylase homologue that exhibits polyadenylation activity may account for the poly(A) tails found in this organism.