title: Association factor of ribosomal subunits from Bacillus stearothermophilus.
abstract: The isolation of a new factor, which can cause the in vitro association of 30S and 50S ribosomal subunits at low Mg(++) concentration, is described. The association factor is eluted together with the dissociation protein when ribosomes of Bacillus stearothermophilus are washed with salt solutions of high concentration. The association activity is heat-stable, whereas dissociation factor is inactivated after 10 min at 80 degrees C. This treatment allows the separation of both factors. Several properties rule out the possibility that uncharged, amino-acyl-, or peptidyl-tRNA are responsible for the association process described in this report. Digestion with trypsin shows that the association factor contains at least two components, one of which is a protein.
mesh_terms: D001407:Bacillus / Q000032:analysis*; D001426:Bacterial Proteins / Q000302:isolation & purification*; D002449:Cell Aggregation; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D004926:Escherichia coli / Q000032:analysis; D006358:Hot Temperature; D008274:Magnesium / Q000494:pharmacology; D011485:Protein Binding; D012270:Ribosomes / Q000032:analysis* / Q000187:drug effects; D014357:Trypsin / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D014357:Trypsin; D008274:Magnesium