DIRECT VISUALIZATION OF A-SITE, P-SITE, AND E-SITE TRANSFER-RNAS IN THE ESCHERICHIA-COLI RIBOSOME

Transfer RNA (tRNA) molecules play a crucial role in protein biosynthe sis in all organisms. Their interactions with ribosomes mediate the tr anslation of genetic messages into polypeptides. Three tRNAs bound to the Escherichia coli 70S ribosome were visualized directly with cryoel ectron microscopy and three-dimensional reconstruction, The detailed a rrangement of A- and P-site tRNAs inferred from this study allows loca lization of the sites for anticodon interaction and peptide bond forma tion on the ribosome.