title: Evidence for specific inhibition of translocation of aminoacyl-transfer ribonucleic acid by the pretreatment of ribosomes of Bacillus subtilis with p-chloromercuribenzoate.
abstract: The biological activities of Bacillus subtilis ribosomes pretreated with 0.5, 1, or 2 mmp-chloromercuribenzoate (PCMB) were examined. The ribosomes treated with 1 or 2 mm PCMB lost their capacity to synthesize polyphenylalanine as well as the capacity to bind phenylalanyl-transfer ribonucleic acid. On the other hand, approximately 70% of the polyphenylalanine synthesis capacity was lost with ribosomes pretreated with 0.5 mm PCMB. This inhibition was found to be due to a specific inhibition of the translocation step. The effect of 0.5 mm PCMB was reversed by 20 mm Mg(2+) without the loss of PCMB bound to ribosomes, while beta-mercaptoethanol partially reversed the inhibitory effect with concomitant loss of bound PCMB.
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001665:Binding Sites; D002247:Carbon Isotopes; D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D002729:Chloromercuribenzoates / Q000494:pharmacology*; D002850:Chromatography, Gel; D002869:Chromosome Aberrations / Q000187:drug effects; D002876:Chromosomes, Bacterial / Q000187:drug effects; D004926:Escherichia coli; D005827:Genetics, Microbial; D008274:Magnesium / Q000494:pharmacology; D008623:Mercaptoethanol / Q000494:pharmacology; D010452:Peptide Biosynthesis; D010441:Peptide Chain Elongation, Translational; D010649:Phenylalanine / Q000378:metabolism; D011072:Poly U; D011691:Puromycin / Q000494:pharmacology; D012343:RNA, Transfer / Q000378:metabolism*; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D002729:Chloromercuribenzoates; D011072:Poly U; D010649:Phenylalanine; D011691:Puromycin; D008623:Mercaptoethanol; D012343:RNA, Transfer; D008274:Magnesium