<Tr> <Td> 5.8 S (160 nt) </Td> </Tr> <Tr> <Td> 5S (120 nt) </Td> </Tr> <Tr> <Td> 40S </Td> <Td> 18S (1874 nt) </Td> <Td> 33 </Td> </Tr> <P> During 1977, Czernilofsky published research that used affinity labeling to identify tRNA - binding sites on rat liver ribosomes . Several proteins, including L32 / 33, L36, L21, L23, L28 / 29 and L13 were implicated as being at or near the peptidyl transferase center . </P>

The three trna-binding site on the ribosome are formed primarily by the rrnas