Alpha-melanocyte stimulating hormone (α-MSH) is a 13-amino-acid peptide hormone responsible for pigmentations in hair and skin. Its peptide sequence is shown.
SYSMQHFRWGKPV
b. Suggest an mRNA sequence for the peptide. Show the 5' and 3' ends.

Question

Alpha-melanocyte stimulating hormone (α-MSH) is a 13-amino-acid peptide hormone responsible for pigmentations in hair and skin. Its peptide sequence is shown.

SYSMQHFRWGKPV

b. Suggest an mRNA sequence for the peptide. Show the 5' and 3' ends.

Accepted Answer

All right. Hello everyone. So this question says that Oxytocin is a peptide hormone involved in childbirth and lactation with a sequence of nine amino acids, Cyiqnc PLG. What is the Mrna sequence for this peptide showing the five prime and three prime S? All right. So this is the kind of question where we're essentially going to have to work backwards according to the process of translation. In other words, from the amino acid sequence, given we're going to have to work backwards to find the corresponding MRN A sequence. So first, let me write out the amino acid sequence. So that's CY I QNC PLG. Now, just for the sake of simplicity, let's start by finding the three letter abbreviations of the amino acids. Given here. C for example is cysteine. So it's cys why is tyrosine Tyr I is isoleucine IOE Q is glutamine GLN N is a spare gene. So it's a SN C is still cysteine. So that's cys once more P is proline pr O L is lucine L eu NG is glycine gly. Let me just move this sequence up to the side here. So here is our amino acid sequence represented in our three letter abbreviations. Now, normally this sequence would be obtained by having a sequence of MRN A coons and using the genetic code table to match them to an amino acid. So in this case, we are working backwards, right, using the genetic code table, we are to identify codons that would code for each of the amino acids that we have here. Now recall that multiple codons can code for the same amino acid. And this is true of all of the amino acids that are listed in our sequence. So just for the sake of simplicity, once you've identified one coon for each amino acid, let's use the first coon listed for each amino acid. So cysteine for example, would be UGU tyrosine would be uau isoleucine is a uu glutamine, is CAA asparagine is a AU proline would be CC. Lucine would be uu A and glycine would be GG. So these are the individual coones. But recall that cysteine has been repeated twice. So the second cysteine residue is in between our, let's see here. It's in between asparagine and prolene. So here the code on for asparagine was a AU and the code on for proline was CC. So I'm going to go ahead and make some space in between these two coons just to go ahead and repeat the code on for Sistine just to account for the entire sequence. So that's UGU repeated here within the sequence. All right. So now what do we have so far the entire MRN a sequence combining the chosen coons in the order given by the peptide sequence, we have UGU a AU a UD no uguuau a uu CAA a Auuuccuuuagu. So here, right, we know what coons will result in the given amino acid sequence. But recall that this is not the MRN a strand as a whole, right? Because what else is needed during the process of translation During the process of translation, we need a start code on to signify the beginning of translation and we need a stop code on to signify the end of translation for that specific polypeptide. So here in addition to the sequence for the amino acids that we already have, we must add a start code on at the beginning and a stop code on at the end of the sequence. So here our start code on is Aug and recall that we have a few different stop codons. For example, we have UAAUAG or UG A for the sake of simplicity, let's go with UA A at the very end. So now we have our completed sequence now to the left is the five prime end and to the right is the three prime end. And with that being said, we have our complete MRN A sequence. So that's a uguguuauauuc a AAA uuguccuuuagguua A. And so with that being said, thank you so very much for watching. And I hope you found this helpful

Alpha-melanocyte stimulating hormone (α-MSH) is a 13-amino-acid peptide hormone responsible for pigmentations in hair and skin. Its peptide sequence is shown.
SYSMQHFRWGKPV
b. Suggest an mRNA sequence for the peptide. Show the 5' and 3' ends.

Verified video answer for a similar problem:

Key Concepts

Peptide Synthesis

mRNA Codons

5' and 3' Ends of mRNA

Alpha-melanocyte stimulating hormone (α-MSH) is a 13-amino-acid peptide hormone responsible for pigmentations in hair and skin. Its peptide sequence is shown.SYSMQHFRWGKPVb. Suggest an mRNA sequence for the peptide. Show the 5' and 3' ends.

Verified video answer for a similar problem:

Key Concepts

Peptide Synthesis

mRNA Codons

5' and 3' Ends of mRNA

Alpha-melanocyte stimulating hormone (α-MSH) is a 13-amino-acid peptide hormone responsible for pigmentations in hair and skin. Its peptide sequence is shown.
SYSMQHFRWGKPV
b. Suggest an mRNA sequence for the peptide. Show the 5' and 3' ends.