Figure 15.22: Structure of the ribosome. (a) Low-resolution model of the ribosome, showing the A, P, and E sites where tRNAs, the mRNA, and the growing polypeptide chain reside. (b) High-resolution model of the ribosome. The tRNA in the E site is reddish brown, the tRNA in the P site is red, and the tRNA in the A site is green. The 16S rRNA is shown in yellow, the 23S rRNA is in cyan, and the 5S rRNA is green. Small ribosomal subunit proteins are shown in orange, whereas large ribosomal subunit proteins are shown in purple. (c) Positions of tRNAs in E, P, and A sites of the ribosome shown in part b.
[Part b: MRC Lab of Molecular Biology, Wellcome Images.]