title: Arrangement of the subunits in the ribosome of Escherichia coli: demonstration by immunoelectron microscopy.
abstract: The three-dimensional locations of Escherichia coli ribosomal proteins S13, L1, and L7/L12 on the surface of ribosomal subunits and 70S monomeric ribosomes were determined by electron microscopy of antibody-labeled ribosomal particles. A new approach to orient the subunits within 70S ribosomes was developed that used 30S.70S.50S triples that were prepared by simultaneous combination with one antibody directed against a 30S protein and another directed against a 50S protein. Electron microscope studies of triples obtained with the antibody combinations anti-S13/anti-L1 and anti-S13/anti-L7/L12 showed that, in 70S monomeric ribosomes, the head of the 30S subunit is proximate to protein L1 and the peptidyl transferase center but far from the rod-like appendage containing proteins L7 and L12.
mesh_terms: D000906:Antibodies; D004926:Escherichia coli / Q000648:ultrastructure*; D007118:Immunoassay; D008854:Microscopy, Electron; D012269:Ribosomal Proteins / Q000032:analysis*; D012270:Ribosomes / Q000648:ultrastructure*
chemical_list: D000906:Antibodies; D012269:Ribosomal Proteins