Polynucleotide phosphorylase has a role in growth of Escherichia coli

Mutants having low levels of polynucleotide phosphorylase activity grow poorly at 45 C. All revertants isolated for their ability to grow better at that temperature also regained higher levels of polynucleotide phosphorylase and the ability to be induced for tryptophanase. Thus, a physiological role is implied for the enzyme polynculeotide phosphorylase.