<p> The of the characterisation of two proteins from <taxon tax_id="1902">Streptomyces coelicolor</taxon> ahs been presented [<cite idref="PUB00034388"/>]. The protein in this family was shown to have poly(A) polymerase activity and may be responsible for polyadenylating RNA in this species. It has also been shown that a nearly identical plasmid-encoded protein from <taxon tax_id="1890">Streptomyces antibioticus</taxon> is a bifunctional enzyme that acts also as a guanosine pentaphosphate synthetase [<cite idref="PUB00034501"/>].</p> Guanosine pentaphosphate synthetase I/polyribonucleotide nucleotidyltransferase