Question

In an in vitro translation experiment, poly(UC) RNA template produced poly(Ser-Leu), while poly(AG) RNA template produced poly (Arg-Glu) polypeptide. Which one of the following options represents correct interpretations of the codons assignments for Ser, Leu, Arg, and Glu.

• A. Ser-UCU, Leu-CUG, Arg-AGA, Glu-GAG
• B. Ser-CUC, Leu-GAG, Arg-UCU, Glu-AGA
• C. Ser-AGA, Leu-UCU, Arg-GAG, Glu-CUC
• D. Ser-GAG, Leu-AGA, Arg-CUC, Glu-UCU

Answer 1

The correct option is A Ser-UCU, Leu-CUG, Arg-AGA, Glu-GAG

A poly(UC) RNA has nucleotide sequence UCUCUCUCUCUC. It codes for amino acid sequence poly(Ser-Leu).

As we know, three codon codes for an amino acid. Hence, in this case, first three codons, that is UCU codes for Ser. The next three codons, that is CUC codes for Leu.

Similarly, a poly(AG) RNA has nucleotide sequence AGAGAGAGAG. It codes for amino acid sequence poly(Arg-Glu).

As we know, three codon codes for an amino acid. Hence, in this case, first three codons, that is AGA codes for Arg. The next three codons, that is GAG codes for Glu.

Thus, the correct answer is option A.