Nucleotide-sequence differences among ribosomal ribonucleic acid fractions and soluble ribonucleic acid from various bacterial species

Abstract

Bacterial RNA fractions with identical base compositions have been compared by digesting the RNA with pancreatic RNAase (EC 2.7.7.16) and determining the relative frequency of nucleotide fragments. 1. There were no detectable differences among several strains of Escherichia coli nor for the same strain grown under a variety of conditions. 2. The 70-S ribosomal RNA's from bacteria with widely varying guanine-cytosine contents of their DNA were compared. There were no detectable differences among bacteria closely related to E. coli. Only species with very high or low guanine-cytosine contents showed considerable differences in their RNA from each other and from E. coli. 3. The 50-S and 30-S RNA's of these species differ from each other and from the corresponding fractions of E. coli. 4. Nucleotide mapping of s-RNA's also showed no detectable differences among species closely related to E. coli but considerable differences for bacteria with high or low guanine-cytosine content of their DNA. The implications of these results in terms of the synthesis and function of the various RNA fractions are discussed.