Present conceptions on the peptidyltransferase centre of animal ribosomes.

: This review deals with results of affinity labelling experiments on proteins of the peptidyl-transferase centre (PTC) of animal ribosomes. From the studies it is concluded that ribosomal proteins L 5, L 21/23, L 32/33, and L 36 are the main candidates for the ribosomal P site and proteins L 6, L 18a, and L 28/29 for the ribosomal A site. Proteins L 10 and L 13/15 seem to be located in a more central region of the PTC. These findings are correlated with results obtained so far by using other techniques. Finally, the data are discussed, and a tentative model on the relative spatial arrangement of certain ribosomal proteins at the PTC is proposed.