Repetitive DNA in Escherichia coli: multiple sequences complementary to small stable RNAs.

Radioactively labeled 4.5S, 6S, and 10S RNAs from Escherichia coli were hybridized to EcoRI fragments from the E. coli genome. Each of these molecules bound to more than one DNA fragment. Cot curve analysis of the kinetics of the annealing of these RNAs to denatured E. coli DNA suggests that the DNA corresponding to each of these molecules is reiterated in the genome. These experiments also suggest that these reiterated sequences are non adjacent.