title: Location of protein S1 of Escherichia coli ribosomes at the 'A'-site of the codon binding site. Affinity labeling studies with a 3'-modified A-U-G analog.
abstract: An affinity analog with a 5-bromoacetamido uridine 5'-phosphate moiety bonded to the 3' end of A-U-G has been prepared with the aid of polynucleotide phosphorylase. This 3'-modified, chemically reactive A-U-G analog was used to probe the ribosomal codon binding site. The yield of the reaction depended strongly on the ribosomal source and was sensitive to salt-washing ribosomes. The major crosslinking product was identified to be protein S1. Since the reaction of this 3'-modified A-U-G programmed ribosomes for Met-tRNA-Met-M binding, it is concluded that protein S1 is located at or near the 3'-side of the ribosomal codon binding site.
mesh_terms: D003062:Codon; D004926:Escherichia coli / Q000378:metabolism*; D005779:Immunodiffusion; D008715:Methionine; D008970:Molecular Weight; D009841:Oligonucleotides / Q000378:metabolism*; D009843:Oligoribonucleotides / Q000378:metabolism*; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012343:RNA, Transfer / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013698:Templates, Genetic
chemical_list: D003062:Codon; D009841:Oligonucleotides; D009843:Oligoribonucleotides; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D012343:RNA, Transfer; D008715:Methionine