Amino acids are not directly incorporated into protein on a messenger RNA template. An amino acid is carried to the mRNA chain by a tRNA molecule. tRNAs are small, about 7080 nucleotides in length, and are folded into precise three-dimensional structures because of hydrogen bonding between bases in particular stretches of the molecule. This gives rise
Cell Biology: A Short Course, Second Edition, by Stephen R. Bolsover, Jeremy S. Hyams, Elizabeth A. Shephard, Hugh A. White, Claudia G. Wiedemann ISBN 0-471-26393-1 Copyright © 2004 by John Wiley & Sons, Inc.
ribosome
ribosome
Cj30s_J
protein
Figure 8.1. Overview of protein synthesis
Cj30s_J
protein
Figure 8.1. Overview of protein synthesis to four double-stranded regions, and it is these that give tRNA its characteristic cloverleaf structure when drawn in two dimensions as in Figure 8.2.
Each tRNA molecule has an amino acid attachment site at its 3' end and an anticodon, three bases that are complementary in sequence to a codon on the mRNA. The tRNA binds to the mRNA molecule because hydrogen bonds form between the anticodon and codon. For example, the codon for methionine is 5' AUG 3' which will base pair with the anticodon 3' UAC 5'.
Was this article helpful?
Post a comment