Three-dimensional localization of the NH2- and carboxyl-terminal domain of ribosomal protein S1 on the surface of the 30 S subunit from Escherichia coli.
Antibodies were raised against Escherichia coli ribosomal protein S1 and its NH2- and COOH-terminal fragments, and their specificity was demonstrated by a variety of immunological techniques. These antibodies were then used to investigate the location of protein S1 and its NH2- and COOH-terminal domains on the surface of the 30 S ribosomal subunit by immunoelectron microscopy. In order to prevent dissociation of the protein during the experiments, S1 was cross-linked to 30 S subunits with dithiobis(succinimidyl-propionate); cross-linking yield was 100%. Epitopes of the NH2-terminal domain of S1 were localized at the large lobe of the 30 S ribosomal subunit, close to the one-third/two-thirds partition on the side which in the 70 S ribosome faces the cytoplasm. Experiments with monovalent Fab fragments specific for the COOH-terminal part of S1 provide evidence that the COOH-terminal domain forms an elongated structure extending at least 10 nm from the large lobe of the small subunit into the cytoplasmic space.
Max-Planck-Institut für Molekulare Genetick, Abt. Wittmann, Berlin, Federal Republic of Germany.
J
J
Walleczek
R
R
Albrecht-Ehrlich
G
G
Stöffler
M
M
Stöffler-Meilicke
D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology; D002499:Centrifugation, Density Gradient; D003432:Cross-Linking Reagents; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli / Q000032:analysis*; D007106:Immune Sera / Q000276:immunology; D007118:Immunoassay; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D012269:Ribosomal Proteins / Q000032:analysis* / Q000276:immunology; D012270:Ribosomes / Q000032:analysis*; D013388:Succinimides
D000941:Antigens; D003432:Cross-Linking Reagents; D000939:Epitopes; D007106:Immune Sera; D007140:Immunoglobulin Fab Fragments; D046911:Macromolecular Substances; D012269:Ribosomal Proteins; D013388:Succinimides; C015494:ribosomal protein S1; C011240:dithiobis(succinimidylpropionate)