Ribonucleic Acid Polymerase from Micrococcus lysodeikticus

The order of efficiency of four single stranded homopolymer templates in directing the incorporation of their respective complementary substrates in the presence of highly purified Micrococcus lysodeikticus RNA polymerase is d(T)n g r(A)n g r(U)n g d(A)n under conditions of template saturation. The presence of both ATP and UTP has little influence on the rates observed with r(A)n or r(U)n. With d(A)n or d(T)n, however, the noncomplementary substrate influences the extent of incorporation of the complementary substrate, and both the complementary and the noncomplementary nucleotides are incorporated into product strands. The addition of a second complementary homopolymer exerts a profound stimulatory influence on the template capacity of the first template strand. A polydeoxynucleotide strand is more effective in this enhancement than a polyribonucleotide strand. Furthermore, the enhancement is observed whether or not the second strand is itself serving as a template for RNA polymerase activity. These data are examined with regard to possible rate-governing factors.