Acridine dyes such as proflavin are known to induce primarily single base-pair additions and deletions. Suppose that the wild-type nucleotide sequence in the mRNA produced from a gene is
5¢-AUGCCCUUUGGGAAAGGGUUUCCCUAA-3¢
Also, assume that a mutation is induced within this gene by proflavin and, subsequently, a revertant of this mutation is similarly induced with proflavin and shown to result from a second-site suppressor mutation within the same gene. If the amino acid sequence of the polypeptide encoded by this gene in the revertant (double mutant) strain is
NH2-Met-Pro-Phe-Gly-Glu-Arg-Phe-Pro-COOH
what would be the most likely nucleotide sequence in the mRNA of this gene in the revertant (double mutant)?