title: Sites of ribosomal RNAs involved in the subunit association of tight and loose couple ribosomes.
abstract: It was demonstrated previously by kethoxal treatment studies that tight (TC) and loose (LC) couple ribosomes use different sites of the 16 S and 23 S RNAs for subunit association (Burma, D. P., Srivastava, A. K., Srivastava, S., and Dash, D. (1985) J. Biol. Chem. 260, 10517-10525). To localize these sites, a number of oligodeoxynucleotides complementary to the suspected sites of the 16 S and 23 S RNAs were synthesized, and their binding to ribosomes and effects on subunit association were studied. Some of the probes inhibit the association of both TC and LC ribosomes, some inhibit the association of TC but not LC ribosomes, and some inhibit the association of LC but not TC ribosomes. It appears that both TC and LC ribosomes use one common site of association, bases 818-823 of the 16 S and 2308-2313 of the 23 S RNA. The second site, 788-793 of the 16 S RNA and 2753-2758 of the 23 S RNA for TC ribosomes, and 783-791 of the 16 S RNA and 2295-2303 of the 23 S RNA for LC ribosomes, is not shared. This suggests a spatial movement of the ribosomal subunits with respect to one another and lends further support to the model of translocation based on the interconversion of TC and LC ribosomes.
authors.affiliation: Molecular Biology Unit, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Agrawal
authors.forename: D P
authors.initials: DP
authors.lastname: Burma
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D009838:Oligodeoxyribonucleotides; D012338:RNA, Ribosomal, 23S