On the biosynthesis of bacterial ribosomal RNA

Occurrence in Bacillus licheniformis of two species of 5-S RNA with multiple differences in primary structure

Bacillus licheniformis was found to contain two species of 5-S RNA. One of these, the primary structure of which has been published previously [H. A. Raué, T.J. Stoof and R.J. Planta (1975) Eur. J. Biochem. 59, 35--42] accounts for 80--90% of the total cellular amount of 5-S RNA. The other one, comprising 10--20% of the total amount, differs in primary structure from the major species at eight positions. All base changes are either purine leads to purine or pyrimidine leads to pyrimidine substitutions. Half of the changes are located within the 5'-terminal part (15 nucleotides) of the molecule, the other half in the 3'-terminal region (22 nucleotides). At least one of the base changes is in a region which in B. subtilis has been implicated in processing of precursor 5-S RNA. The data are consistent with the existence of a single 5-S RNA cistron with a primary structure different from that of all other 5-S RNA cistrons in B. licheniformis.

Nucleotide sequence of 5-S RNA from Bacillus licheniformis

The complete nucleotide sequence of 5-S RNA from Bacillus licheniformis was determined by analysis of complete and partial digests obtained with either T1 or pancreatic ribonuclease. The molecule was found to have a length of 116 nucleotides and may possess a minor sequence heterogeneity. There is a large degree of homology between the sequence of B. licheniformis 5-S RNA and those published for 5-S RNA from B. megatherium and B. stearothermophilus. The difference between the three 5-S RNA species are limited mainly to the two terminal and one internal sequence. B. licheniformis 5-S RNA contains the sequence U95-G-A-G-A-G100, which in B. subtilis has been implicated in the processing of precursor 5-S RNA. Possible models for the secondary structure of prokaryotic 5-S RNA are discussed on the basis of the results of limited digestion of B. licheniformis 5-S RNA by ribonuclease T1.