Anti-parallel pairing of mRNA codons and tRNA
anti-codons
Each mRNA codon consists of three
nucleotides that pair with the tRNA in the 5'3'. The
corresponding tRNA anticodon loop includes
three nucleotide positions complementary to the codon.
Given a 5'3' codon
sequence, the complementarity of the
tRNA
anticodon is most easily seen in the anti-complementary
direction. However this would violate our convention of
describing nucleic acids only 5'3'.
In the above diagram, a 5'-AUG-3'
codon in the mRNA would pair with a 3'-UAC-5'
anticodon in the tRNA,
which written out in the conventional way is a 5'-CAU-3'
anticodon.
Figure © 2012 TA Brown, Introduction to Genetics (1st ed.); additional text © 2012 by Steven M. Carr