Question

Describe the essential structural features of a mature, 1,800 nucleotide long mRNA that would allow it to efficiently translate a 237 amino acid protein.

Answer 1

Given is a 1800 nucleotide long mRNA that codes for only 237 amino acids. We know that a codon is a nucleotide triplet that codes for a single amino acid. As such 1800 nucleotides can code for 600 amino acids (1800/3). However, there are only 237 amino acids coded by the mRNA. Also the mRNA is a mature mRNA which means that it has already undergone the process of splicing and is consisted of only exons. Therefore the possible reason behind coding 237 amino acids though it had the potential to code for 600 is that it includes a stop codon at the 237*3=711th nucleotide. As such the last amino acid encoded is the 237th one and translation stops. Thus the 711th nucleotide must be either of UAA OR UAG OR UGA which are the 3 stop codons.