Differential localization of two epitopes of Escherichia coli ribosomal protein L2 on the large ribosomal subunit by immune electron microscopy using monoclonal antibodies.
Two monoclonal antibodies (mAb), directed toward different epitopes of Escherichia coli ribosomal protein L2, have been used as probes in immune electron microscopy. mAb 5-186 recognizes an epitope within residues 5-186 of protein L2; it is seen to bind to 50 S subunits at or near the peptidyl transferase center, beside the subunit head on the L1 shoulder. mAb 187-272 recognizes an epitope within residues 187-272. This antibody binds to the face of the 50 S subunit, below the head and slightly toward the side with the stalk; this site is near the translocation domain. Both antibodies can bind simultaneously to single subunits. This indicates that protein L2 is elongated, reaching from the peptidyl transferase center to below the subunit head and approaching the translocational domain. The different locations of the two epitopes are consistent with previous biochemical results with the two antibodies (Nag, B., Tewari, D. S., Etchison, J. R., Sommer, A., and Traut, R. R. (1986) J. Biol. Chem. 261, 13892-13897).
Department of Biological Chemistry and Molecular Biology Institute, UCLA School of Medicine, University of California 90024.
H M
HM
Olson
B
B
Nag
J R
JR
Etchison
R R
RR
Traut
D G
DG
Glitz
D000911:Antibodies, Monoclonal / Q000276:immunology; D000936:Antigen-Antibody Complex; D000939:Epitopes; D004926:Escherichia coli / Q000648:ultrastructure*; D008854:Microscopy, Electron; D010446:Peptide Fragments / Q000276:immunology; D010458:Peptidyl Transferases / Q000648:ultrastructure; D012269:Ribosomal Proteins / Q000276:immunology*; D012270:Ribosomes / Q000648:ultrastructure*
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D000939:Epitopes; D010446:Peptide Fragments; D012269:Ribosomal Proteins; C029466:ribosomal protein L2; D010458:Peptidyl Transferases