in 1955, marianne grunberg-manago and severo ochoa had reported the isolation of an enzyme that catalyzed the synthesis of rna. this enzyme was at first hoped to be responsible for the synthesis of rna in cells, and ochoa's discovery was honored with a nobel prize in 1959. however, it was later realized that ochoa's enzyme did not use dna to synthesize rna but instead formed arbitrary sequences, and later this enzyme was found to degrade rna in cells. undeterred by ochoa's findings, hurwitz searched for a cellular rna polymerase on his own and in 1960 he reported the isolation of rna polymerase activity from "escherichia coli" extracts. remarkably, several other research groups reported similar discoveries at roughly the same time (samuel b. weiss, audrey stevens, and james bonner). hurwitz continued his research on rna synthesis, and in 1962 hurwitz, john j. furth, and monika anders reported the purification of rna polymerase.