Question

Part 1: The basis for molecular regulation of gene expression is through base-pairing of complementary sequences. Often the sequences that are targeted are those that are critical in initiating translation (such as the Shine Dalgarno sequence and initiation codon of an mRNA). Base-pairing at these key regions blocks access of ribosomes, and in this case, translation initiation would be prevented. To help you understand this base-pairing mechanism, let's start with a sequence of a made up regulatory RNA. 5'- AGCCAUCGGUAUCGACCUCCUGG-3'. The goal here is for you to determine which of the mRNA sequences listed below, could be regulated by our made up regulatory RNA. Specifically, we are focusing on regulation in terms of inhibiting translation initiation. To answer this fully, you'll have to recall the rules of base-pairing that we have discussed many times in class! You must indicate which RNA you believe to be regulated (1pt), and then give a description as to why you came to this conclusion (2pts). a) 3' - UTGCTGUUCGGTCCTCCUGCTUTGGCTUCCGUTCGUTGUTCGTUGCGGGUTUTTTTCCC...-5' b) 5'- CCCTTTTUTUGGGCGUTGCTUGTUGCTUGCCUTCGGTUTCGUCCTCCTGGCUUGTCGTU...-3' c) 5'- UACGACUUGCCAGGAGGUCGAUACCGAUGGCUAGCUACUAGCAUCGCCCUAUAAAAGGG...-3' d) 5'- GGGAAAAUAUCCCGCUACGAUCAUCGAUCGGUAGCCAUAGCUGGAGGACCGUUCAGCAU...-3' e) 3' - UACGACUUGCCACGUGGUCGAUACCGAUAGCUAGCUACUAGCAUCGCCCUAUAAAAGGG...-5'

Please chose A, B, C, D, or E and explain why/how you came to this conclusion

Answer 1

Among all the mRNA molecules option c mRNA is regulated by this regulatory sequence.

As initial 2 sequence a and b are not mRNA as they have thymine.

And among c,d,and e sequence only C sequence is able to hybridize with regulatory sequence due to this hybridization, this mRNA at translation start codon , there will inhibition of translation initiation.