The Complete Nucleotide Sequence of the Ribosomal 16-S RNA from Escherichia coli. Experimental Details and Cistron Heterogeneities

The complete nucleotide sequence of the 16-S RNA from Escherichia coli has been determined using rapid RNA-sequencing gel methods. The experimental data are fully described in this paper. The specificities of the ribonucleases, especially the ribonuclease PhyI are discussed and the consequences of the persistence of stable secondary structure are considered. The proposed sequence contains 1541 nucleotides and agrees completely with the DNA sequence of the rrnB cistron deduced by Brosius, J., Palmer, M.L., Kennedy, P.J., and Noller, H.F. Proc. Natl. Acad. Sci. U.S.A. (1978) 75, 4801-4805. But there are several cistron heterogeneities of which we described 16 single-base heterogeneities, 7 of the deletion/insertion type and 9 of the transition or transversion type. Our observations suggest the existence, among the 7 ribosome RNA cistrons, of one or two mutated ones. The respective advantages and disadvantages of both RNA and DNA sequencing methods are discussed.