Inference of
the Universal Genetic Code from poly-monomers &
poly-dimers
Results from the poly U, C, A, &
G RNA messages allows the inference that UUU,
CCC, AAA, & GGG coded for F, P K, &
G respectively.
Preparation and polymerization of dinucleotides yields a
polynucleotide with two alternating
triplets irrespective of the starting point. Thus UC-UC-UC
for example produces repeating UCU-CUCtriplets, and a polypeptide
with alternative S &L residues. Note
that of the twelve possible dinucleotides, the alternative pair
with the letters reversed produces the same pair of
alternating peptide.
Use of all possible dinucleotides gives codons for 12 amino acids,
including redundant codons CGC and AGA for R;
note the degeneracy at the 2nd bases is unusual. In
combination with the mono-nucleotide codons, this solves exactly one
codon in each of the boxes defined by the first two
bases in the codon. These experiments would not identify any of
the three stop codons (no experiments should 'fail' because they
incorporate nothing), and the 15 amino acids assigned codons do
not include W Q M N or D or the unusual codons
for L' and S'.
