This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Body, B A Articles by Brownstein, B H Search for Related Content PubMed PubMed Citation Articles by Body, B A Articles by Brownstein, B H

 Previous Article  |  Next Article 

J Bacteriol. 1976 June; 126(3): 1149-1155

Ribosomal precursor particles of Bacillus megaterium.

ABSTRACT

Pulse-labeled cells of Bacillus megaterium were converted to protoplasts, and lysates of the protoplasts were analyzed by sucrose gradient sedimentation. Precursor ribonucleoprotein (RNP) particles then appeared predominantly as 50S and 30S precursor ribosomal subunits. Polyacrylamide gel electrophoresis of the ribosomal ribonucleic acid from the 50S and 30S RNP particles confirmed their precursor nature since they were shown to contain precursor 23S and 16S ribosomal ribonucleic acid, respectively. Treatment of protoplast lysates with 0.5% deoxycholate prior to sedimentation analysis resulted in a markedly different radioactivity profile. The 50S RNP particles were no longer present, but 43S particles were observed in addition to increased amounts of pulse-labeled material sedimenting at 30S and slower. Extracts from cells broken in a French press showed a profile from sucrose gradient sedimentation similar to that of the deoxycholate-treated protoplast lysate. These data suggest that the nature of the precursor ribosomal particles appears to be a function of the method of cell disruption or detergent treatment of the cell extract preparation. The observed 50S and 30S RNP particles may be the major precursor ribosomal subunits in vivo; the slower-sedimenting species could result from some form of breakdown or change in the configuration of the 50S and 30S precursors.