The First Nucleotide of the Codon Located in the P Site of the 80S Ribosome Is Close to G1702 of the 18S rRNA as Revealed by Crosslinking to a pUUUGUU Derivative Containing a Perfluorophenylazido Group at the Guanine

摘要

Modification of the 18S rRNA with a pUUUGUU derivative carrying a perfluorophenylazido group at N7 of G was studied in the complex with the human 80S ribosome and Val-tRNA~(Val),which directs modified GUU to the P site.Reverse transcription reported modification of invariant G1702.of the 18S rRNA.On evidence of the results and the earlier data on affinity modification of the human ribosome with tetra- or heptari-bonucleotide derivatives carrying an alkylating group at the 3' end,the template was assumed to make a bend between the A- and P-site codons,which brings both codons closer to G1702 of the 18S rRNA.