title: Immune electron microscopic localization of dinitrophenyl-modified ribosomal protein S19 in reconstituted Escherichia coli 30 S subunits using antibodies to dinitrophenol.
abstract: Escherichia coli small ribosomal subunits have been reconstituted from RNA and high performance liquid chromatography-purified proteins including protein S19 that had been modified at its amino-terminal proline residue with 1-fluoro-2,4-dinitrobenzene. As detailed in the accompanying paper (Olah, T. V., Olson, H. M., Glitz, D. G., and Cooperman, B. S. (1988) J. Biol. Chem. 263, 4795-4800), dinitrophenyl (DNP)-S19 was efficiently incorporated into the site ordinarily occupied by S19. Antibodies to DNP bound effectively to the reconstituted subunits and did not cause dissociation of the modified protein from the subunit. Electron microscopy of the immune complexes was used to localize the modified protein on the subunit surface. More than 95% of the antibody binding sites seen were consistent with a single location of protein S19 on the upper portion or head of the subunit, on the surface that faces the 50 S particle in a 70 S ribosome, and in an area relatively distant from the subunit platform. The S19 site is close to the region in which 30 S subunits are photoaffinity labeled with puromycin. Protein S19 is thus near protein S14 in the small subunit and in proximity to the peptidyl transferase center of the 70 S ribosome.
authors.affiliation: Department of Biological Chemistry, UCLA School of Medicine 90024.
authors.forename: H M
authors.initials: HM
authors.lastname: Olson
authors.forename: T V
authors.initials: TV
authors.lastname: Olah
authors.forename: B S
authors.initials: BS
authors.lastname: Cooperman
authors.forename: D G
authors.initials: DG
authors.lastname: Glitz
mesh_terms: D000906:Antibodies; D004139:Dinitrofluorobenzene; D004926:Escherichia coli / Q000648:ultrastructure*; D007118:Immunoassay; D008854:Microscopy, Electron; D008961:Models, Structural; D009578:Nitrobenzenes; D012269:Ribosomal Proteins / Q000032:analysis* / Q000276:immunology; D012270:Ribosomes / Q000648:ultrastructure*
chemical_list: D000906:Antibodies; D009578:Nitrobenzenes; D012269:Ribosomal Proteins; C040343:ribosomal protein S19; D004139:Dinitrofluorobenzene