title: [Structural studies of translating ribosomes. II. Comparative sedimentation analysis of pre- and post-translocation states].
abstract: Using the solid-phase translation system technique where template poly(U) is covalently coupled to Sepharose through cleavable disulfide bridges translating monoribosomes carrying a polypeptide (polyPhe) of 10 to 20 amino acids long have been isolated. Both pre-translocation state and post-translocation state ribosomes have been obtained. It has been shown that the sedimentation coefficient of the pre-translocation state ribosomes exceeds that of the post-translocation state ribosomes by a magnitude of about 1S. This difference is independent on the sedimentation rate (hydrostatic pressure) in the range of 20 000 to 40 000 rev/min and, most likely, is not a direct contribution of the increase of the particle mass at the expense of an additional tRNA in the pre-translocation state ribosomes. Together with other data, this result suggests that translating ribosomes in the pre-translocation state are more compact than post-translocation state ribosomes.
mesh_terms: D002499:Centrifugation, Density Gradient; D004926:Escherichia coli; D008722:Methods; D010441:Peptide Chain Elongation, Translational; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000032:analysis / Q000235:genetics*; D012335:RNA, Ribosomal / Q000032:analysis / Q000235:genetics*; D012270:Ribosomes / Q000032:analysis*; D013997:Time Factors
chemical_list: D012329:RNA, Bacterial; D012335:RNA, Ribosomal
vernacular_title: Strukturnye issledovaniia transliruiushchikh ribosom. II. Sravnitel'nyĭ sedimentatsionnyĭ analiz pre- i post-translokatsionnykh sostoianiĭ.