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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