Question

The sequence below corresponds to a DNA segment in which the bottom strand is the template.

3’ –A A T C G C A C A C C G G A G G T A - 5’

5’ –T T A G C G T G T G G C C T G C A T – 3’

The amino acid residue sequence starting from the N-terminal will be:

Select one:

a. Met – Glu – Ala – Thr – Arg

b. Arg – Thr – Ala – Glu – Met

c. Tyr – Leu – Arg – Cys – Ala – Ile

d. Leu – Ala – Cys – Gly – Leu - His

e. Asn – Arg – Thr – Pro – Glu – Val

f. None of the answers is correct.

Answer 1

f. None of the answer is correct

Explanation:

According to the question the bottom strand is template stand .IN case of mRNA synthesis the template strand is always in 3' to 5' direction and all mRNA synthesized in the 5' to 3' direction .

So arranging the template strand in the direction of 3' to 5' I get this---

3'- TACGTCCGGTGTGCGATT- 5' Template strand

5'- AUGCAGGCCACACGCUAA- 3’ mRNA

AS AUG codon is for Met(methionine), CAG codon is for Gln (glutamine), GCC codon is for Ala(alanine), ACA codon is for Thr(threonine), CGC codon is for Arg(arginine), UAA codon is stop codon.

From this mRNA the amino acid will synthesise and the amino acid sequence starting from the N terminal will be—

Met – Gln – Ala – Thr – Arg

As this sequence is not listed in the option, so the right answer is none of the answer is correct.