Answer to Question #147278 in Molecular Biology for Kai Lynn

Question

The following RNA sequence can be read in two different directions. Describe how the two interpretations differ:
AUGACAAAAGGUUAC

Explain how the amino acid sequence would change if the C in the second codon were deleted. Identify what kind of mutation would happen.

Answer 1

• The two interpretations differ in the sequence of amino acids that can be added onto a forming polypeptide chain. In the first interpretation the sequence of amino acids coded is a s thus;

AUG ACA AAA GGU UAC

Met - Thr - Lys - Gly - Ile

While the second interpretation codes for the following sequence of amino acids;

CAU UGG AAA ACA GAU

His -Trp - Lyc - Thr - STOP

Thus the two interpretations will result in a different protein.

• A deletion at base C in the second codon will result in a frameshift type of gene mutation; that will result in a complete alteration of the amino acid sequence on the forming polypeptide chain. The deletion will affect every codon in the particular genetic sequence, thus every single resultant codon in the mutant DNA would code for a new amino acid, resulting in completely different polypeptide chain during translation.

Wild DNA sequence

AUG ACA AAA GGU UAC

Met - Thr - Lys - Gly - Ile

Mutant DNA sequence

AUG AAA AAG GUU AC_

Met - Lys - Lys - Val -Thr

(START)