It is possible to predict the minimum number of tRNAs required to translate the different codons specifying a particular amino acid.
The amino acid leucine is specified by six codons: UUA, UUG, CUU, CUC, CUA and CUG.
The first two letters of two codons are UU and of four codons CU.
Hence at least two different tRNAs are required, since the first two letters of a codon do not have wobble pairing with the anticodon.
Of the four codons having CU two (CUU and CUC) have pyrimidines as their third bases and two (CUA and CUG) have purines.
Hence they cannot be read by the same anticodon, because the purine of the anticodon can only pair with a pyrimidine and vice versa.
The CU codons must therefore be read by at least two different anticodons.
Thus at least three co dons are required to read the anticodons for leucine.
Presumably the anticodons AUU reads UUA and UAG, GAA reads CUU and CUC, and GAU reads CUA and CUG. It will be seen that each anticodon has Watson-Crick pairing with third base of one codon, and wobble pairing with the third base of the other codon.
