microRNA question

[Sophie]

A section of the coding strand of the DNA sequence of a gene that is expressed in a healthy human liver cell is 5′-ATGCGCCGTAT-3′.

A microRNA (miRNA) regulates this gene by signalling an enzyme to cleave the mRNA corresponding to this section.

What would the sequence be for the miRNA that regulates this gene?

A 3′-AUGCGCCGUAU-5′

B 3′-TACGCGGCATA-5′

C 5′-ATGCGCCGTAT-3′

D 5′-UACGCGGCAUA-3′

E 5′-UAGCGCCGUAU-3′

So far I know that the mRNA sequence is 5’-AUGCGCCGUAU-3’ but don’t know what to do next. The answer is A.

[SohamPaikaray]

The mRNA would be complementary to the coding strand - not what you’ve stated as what the mRNA strand - and the miRNA would be complementary to that mRNA sequence, ending up similar to the coding strand except the T has been swapped out

[Sophie]

Isn’t the mRNA complementary to the DNA template stand?

[Lavanya]

Yes, you are correct

[Sophie]

Thanks for the clarification. Here’s what I got for each sequence:

Coding strand: 5′-ATGCGCCGTAT-3′
Template strand: 3′-TACGCGGCATA-5′
mRNA: 5′-AUGCGCCGUAU-3′
miRNA: 3′-UACGCGGCAUA-5′

What am I doing wrong here?

[SohamPaikaray]

Ahhh I misread it, yes I didn’t realise it said coding strand, Im now just as confused

Where did you find this question?