Q17.4-5ITD - Campbell Biology

Question

(a) Based on the logo, what five adjacent base positions in the 5' UTR region are most likely involved in ribosome binding? Explain. (b) What is represented by the bases in positions 0-2?

Step-by-Step Solution

Answer

1. The tallest stacks with the 5' UTR are present in the position from -12 to -8. These adjacent five bases are the ribosomal binding sites.

2. The bases present in the position, such as 0-2, represent the start codon.

Step 1: Description of the untranslated region (UTR)

The un-translated region present in the gene sequence helps localize the mRNA and maintains the mRNA's stability. The UTR represented in the 5' prime region is known as the leader sequence. It also controls the translation efficiency.

Step 2: Explanation for part “a”

The adjacent position, namely -12 to -8, possesses the tallest stacks in the 5' UTR that acts as the ribosomal binding site. It can regulate the process of translation. 

Step 3: Explanation for part “b”

The bases A, T, G are present in a position 0-2. AUG codes for the start codon methionine in the mRNA produced from the sequenced DNA strand. The start codon is the initiation point of the translation process.