title: Immunochemical accessibility of ribosomal protein S4 in the 30 S ribosome. The interaction of S4 with S5 and S12.
abstract: The reactivity of protein S4-specific antibody preparations with 30 S ribosomal subunits and intermediates of in vitro subunit reconstitution has been characterized using a quantitative antibody binding assay. Anti-S4 antibody preparations did not react with native 30 S ribosomal subunits; however, they did react with various subunit assembly intermediates that lacked proteins S5 and S12. The inclusion of proteins S5 and S12 in reconstituted particles resulted in a large decrease in anti-S4 reactivity, and it was concluded that proteins S5 and S12 are primarily responsible for the masking of S4 antigenic determinants in the 30 S subunit. The effect of S5 and S12 on S4 accessibility is consistent with data from a variety of other approaches, suggesting that these proteins form a structural and functional domain in the small ribosomal subunit.
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D001666:Binding Sites, Antibody; D004587:Electrophoresis, Agar Gel; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli; D001411:Geobacillus stearothermophilus / Q000032:analysis; D007106:Immune Sera; D005779:Immunodiffusion; D046911:Macromolecular Substances; D012269:Ribosomal Proteins / Q000276:immunology; D012270:Ribosomes / Q000032:analysis* / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D000939:Epitopes; D007106:Immune Sera; D046911:Macromolecular Substances; D012269:Ribosomal Proteins; C034212:ribosomal protein S12; C031798:ribosomal protein S4; C030831:ribosomal protein S5