title: The effect of aminoacyl- or peptidyl-tRNA at the A-site on the arrangement of deacylated tRNA at the ribosomal P-site.
abstract: Photoreactive derivatives of E. coli tRNAPhe bearing arylazido groups on guanine residues (azido-tRNA) were used for affinity labelling of E. coli ribosomes in the region of the P-site when the A-site was either free or occupied by aminoacyl- or peptidyl-tRNA. Corresponding complexes of azido-tRNA with ribosomes and poly(U) were obtained both nonenzymatically and with the use of elongation factors. UV-irradiation of the complexes resulted in labelling of ribosomal proteins (preferentially of 30 S subunit). Proteins S9 and S21 were labelled only when the A-site was free; S14 - only when it was occupied; S11, S13, S19 - in both cases; S5, S7, S12, S20 - in some states.
mesh_terms: D000345:Affinity Labels; D001386:Azides / Q000378:metabolism*; D001665:Binding Sites; D004926:Escherichia coli; D010444:Peptide Elongation Factor Tu; D010445:Peptide Elongation Factors / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D010777:Photochemistry; D011072:Poly U / Q000378:metabolism; D012329:RNA, Bacterial / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D000345:Affinity Labels; D001386:Azides; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; D012346:RNA, Transfer, Amino Acyl; D012269:Ribosomal Proteins; C038012:tRNA, azidophenylalanine-; D011072:Poly U; D010649:Phenylalanine; D010444:Peptide Elongation Factor Tu