Question

Examine the following two DNA template sequences. Sequence 1: TACGCTACGATCGTA Sequence 2: TACGCTACTATCGTA If both of these sequences code for proteins, how might the function of protein 2 differ from the function of protein 1

Answer 1

Sequence code

Explanation:

DNA template (non coding strand) is always synthesized from 3'-5' direction and the complementary strand (coding strand) will be synthesized from 5'-3' direction; mRNA synthesized will be from 5'-3' direction and will have the same sequence as coding strand(only in place of T, U will be present)

Sequence 1: 3' TACGCTACGATCGTA 5'

Coding strand 1 : 5' ATGCGATGCTAGCAT 3'

mRNA 1: 5' AUGCGAUGCUAGCAU 3'

AUG codes for methionine(Met); CGA codes for alanine(Ala); UGC codes for threonine(Thr); UAG codes for isoleucine(Iso); CAU codes for valine(Val)

so protein 1 will be:

Met-Ala-Thr-Iso-Val

Sequence 2: 3' TACGCTACTATCGTA 5'

Coding strand 2: 5' ATGCGATGATAGCAT 3'

mRNA 2; 5' AUGCGAUGAUAGCAU 3'

AUG codes for methionine(Met); CGA codes for alanine(Ala); UGA codes for threonine(Thr); UAG codes for isoleucine(Iso); CAU codes for valine(Val)

so protein 2 will be:

Met-Ala-Thr-Iso-Val

Both the protein sequence comes out to be same hence function of protein 2 will be same as that of  protein 1