title: Affinity labelling of Escherichia coli ribosomes with a benzylidene derivative of AUGU6 within initiation and pretranslocational complexes.
abstract: Affinity labelling of E. coli ribosomes with the 2',3'-O-[4-(N-2-chloroethyl)-N-methylamino]benzylidene derivative of AUGU6 was studied within the initiation complex (complex I) obtained by using fMet-tRNAMetf and initiation factors and within the pretranslocational complex (complex II) obtained by treatment of complex I with the ternary complex Phe-tRNAPhe.GTP.EF-Tu. Both proteins and rRNA of 30 S as well as 50 S subunits were found to be labelled. Sets of proteins labelled within complexes I and II differ considerably. Within complex II, proteins S13 and L10 were labelled preferentially. On the other hand, within complex I, multiple modification is observed (proteins S4, S12, S13, S14, S15, S18, S19, S20/L26 were found to be alkylated) despite the single fixation of a template in the ribosome by interaction of the AUG codon with fMet-tRNAMetf.
mesh_terms: D000345:Affinity Labels / Q000378:metabolism*; D001665:Binding Sites; D003062:Codon; D042963:Electron Transport Complex II; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism; D009150:Mustard Compounds; D016660:NAD(P)H Dehydrogenase (Quinone); D010088:Oxidoreductases / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D011808:Quinone Reductases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D000345:Affinity Labels; D003062:Codon; D009097:Multienzyme Complexes; D009150:Mustard Compounds; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl; D012269:Ribosomal Proteins; C025881:4(N)-(2-chloroethyl-N-methylamino)benzylamine; D006160:Guanosine Triphosphate; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases; D010444:Peptide Elongation Factor Tu