RNA product distribution obtained during the transcription of poly[d(A—T)] by wheat germ RNA polymerase IIA under various experimental conditions was analyzed by high resolution polyacrylamide gel electrophoresis. Poly[r(A—U)] synthesis proceeded as if wheat germ RNA polymerase II was a non-processive enzyme: a ladder of RNA products of increasing lengths was obtained, which apparently, terminated at every other nucleotide. RNA release was not dependent upon nucleoside triphosphate substrate concentrations. A likely explanation would be that ternary complexes enzyme: DNA: RNA were very much unstable; moreover, oligonucleotides released were not re-used for further elongation by the enzyme.
