title: The ribosome-in-pieces: binding of elongation factor EF-G to oligoribonucleotides that mimic the sarcin/ricin and thiostrepton domains of 23S ribosomal RNA.
abstract: An oligoribonucleotide (a 27-mer) that mimics the sarcin/ricin (S/R) domain of Escherichia coli 23S rRNA binds elongation factor EF-G; the Kd is 6.9 microM, whereas for binding to ribosomes it is 0.7 microM. Binding saturates when EF-G and the S/R RNA are equimolar; at saturation 70% of the input RNA is in complexes with EF-G. Binding of EF-G to S/R RNA does not require GTP but is inhibited by GDP; the inhibition by GDP is overcome by GTP. The effects of mutations of the S/R domain nucleotides G2655, A2660, and G2661 suggest that EF-G recognizes the conformation of the RNA rather than the identity of the nucleotides. EF-G also binds to an oligoribonucleotide (an 84-mer) that has the thiostrepton region of 23S rRNA; however, EF-G binds independently to S/R and thiostrepton oligoribonucleotides.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: A
authors.initials: A
authors.lastname: Munishkin
authors.forename: I G
authors.initials: IG
authors.lastname: Wool
mesh_terms: D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors / Q000378:metabolism*; D011485:Protein Binding; D012338:RNA, Ribosomal, 23S / Q000737:chemistry* / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000378:metabolism; D012270:Ribosomes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012276:Ricin / Q000737:chemistry; D013883:Thiostrepton / Q000737:chemistry / Q000378:metabolism
chemical_list: D009841:Oligonucleotides; D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors; D012338:RNA, Ribosomal, 23S; D012269:Ribosomal Proteins; D012276:Ricin; D013883:Thiostrepton