The Hemoglobing Mutagenesis Page

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This page is designed to help you see what happens when one nucleotide is wrong in a gene. The example established here is for sickle cell and uses the beta subunit of human hemoglobin. You may want to find other genes and try them at another time.

Here is the sequence for the human mRNA that encodes the alpha subunit of hemoglobin:

(5' UTR -->) ACUCUUCUGG UCCCCACAGA CUCAGAGAGA ACCCACC
(START CODON -->)AUG GUGCUGUCUC CUGCCGACAA GACCAACGUC AAGGCCGCCU GGGGCAAGGU UGGCGCGCAC GCUGGCGAGU AUGGUGCGGA GGCCCUGGAG AGGAUGUUCC UGUCCUUCCC CACCACCAAG ACCUACUUCC CGCACUUCGA CCUGAGCCAC GGCUCUGCCC AGGUUAAGGG CCACGGCAAG AAGGUGGCCG ACGCGCUGAC CAACGCCGUG GCGCACGUGG ACGACAUGCC CAACGCGCUG UCCGCCCUGA GCGACCUGCA CGCGCACAAG CUUCGGGUGG ACCCGGUCAA CUUCAAGCUC CUAAGCCACU GCCUGCUGGU GACCCUGGCC GCCCACCUCC CCGCCGAGUU CACCCCUGCG GUGCACGCCU CCCUGGACAA GUUCCUGGCU UCUGUGAGCA CCGUGCUGAC CUCCAAAUAC CGUUAAGCUG GAGCCUCGGU AGCAGUUCCU CCUGCCAGAU GGGCCUCCCA ACGGGCCCUC CUCCCCUCCU UGCACCGGCC CUUCCUGGUC UUUGAAUAAA GUCUGAGUGG GCGGC

Here is the sequence of the DNA CODING STRAND for human mRNA that encodes the alpha subunit of hemoglobin (note the orientation of the DNA):

3' end
Start condon -->
TACCACGACAGAGGACGGCTGTTCTGGTTGCAGTTCCGGCGGACCCCGTTCCAACCGCGCGTGCGACCGCTCATACCACGCCTCCGGG
ACCTCTCCTACAAGGACAGGAAGGGGTGGTGGTTCTGGATGAAGGGCGTGAAGCTGGACTCGGTGCCGAGACGGGTCCAATTCCCGGT
GCCGTTCTTCCACCGGCTGCGCGACTGGTTGCGGCACCGCGTGCACCTGCTGTACGGGTTGCGCGACAGGCGGGACTCGCTGGACGTG
CGCGTGTTCGAAGCCCACCTGGGCCAGTTGAAGTTCGAGGATTCGGTGACGGACGACCACTGGGACCGGCGGGTGGAGGGGCGGCTCA
AGTGGGGACGCCACGTGCGGAGGGACCTGTTCAAGGACCGAAGACACTCGTGGCACGACTGGAGGTTTATGGCAATTCGACCTCGGAG
CCATCGTCAAGGAGGACGGTCTACCCGGAGGGTTGCCCGGGAGGAGGGGAGGAACGTGGCCGGGAAGGACCAGAAACTTATTTCAGAC
TCACCCGCCG
5' end

Here is the sequence for the human mRNA that encodes the beta subunit of hemoglobin:

(5' UTR -->) ACAUUUGCUU CUGACACAAC UGUGUUCACU AGCAACCUCA AACAGACACC
(START CODON -->)AUG GUGCACC UGACUCCUGA GGAGAAGUCU GCGGUUACUG CCCUGUGGGG CAAGGUGAAC 60
GUGGAUGAAG UUGGUGGUGA GGCCCUGGGC AGGCUGCUGG UGGUCUACCC UUGGACCCAG 120
AGGUUCUUUG AGUCCUUUGG GGAUCUGUCC ACUCCUGAUG CAGUUAUGGG CAACCCUAAG 180
GUGAAGGCUC AUGGCAAGAA AGUGCUCGGU GCCUUUAGUG AUGGCCUGGC UCACCUGGAC 240
AACCUCAAGG GCACCUUUGC CACACUGAGU GAGCUGCACU GUGACAAGCU GCACGUGGAU 300
CCUGAGAACU UCAGGCUCCU GGGCAACGUG CUGGUCUGUG UGCUGGCCCA UCACUUUGGC 360
AAAGAAUUCA CCCCACCAGU GCAGGCUGCC UAUCAGAAAG UGGUGGCUGG UGUGGCUAAU 420
GCCCUGGCCC ACAAGUAUCA CUAA

Here is the sequence of the DNA CODING STRAND for human mRNA that encodes the beta subunit of hemoglobin (note the orientation of the DNA):

3' end
Start condon -->
TACCACGTGGACTGAGGACTCCTCTTCAGACGCCAATGACGGGACACCCCGTTCCACTTGCACCTACTTCAACCACCACTCCGGGACCCG
TCCGACGACCACCAGATGGGAACCTGGGTCTCCAAGAAACTCAGGAAACCCCTAGACAGGTGAGGACTACGTCAATACCCGTTGGGATTC
CACTTCCGAGTACCGTTCTTTCACGAGCCACGGAAATCACTACCGGACCGAGTGGACCTGTTGGAGTTCCCGTGGAAACGGTGTGACTCA
CTCGACGTGACACTGTTCGACGTGCACCTAGGACTCTTGAAGTCCGAGGACCCGTTGCACGACCAGACACACGACCGGGTAGTGAAACCG
TTTCTTAAGTGGGGTGGTCACGTCCGACGGATAGTCTTTCACCACCGACCACACCGATTACGGGACCGGGTGTTCATAGTGATT
5' end

Directions to see what happens in sickle cell:

1. Click and drag across the top line of DNA sequence for the beta subunit. You must use the DNA CODING STRAND!
2. Copy this sequence, then paste it in the box on a new web page - Click here to insert your sequence of interest.
3. After you have inserted the sequence, click on the "Execute" button.
4. Watch the DNA be transcribed into mRNA and then translated into protein.
5. Below you will find a window that contains your original DNA sequence printed a second time. To the left are the words "Delete or add a nucleotide:". In your sequence, find (you will have to put the cursor in the box and use the arrow keys to move to the right) GGACTCC and change it to GGACaCC.
6. Click on the Execute button and notice the seventh amino acid has been changed from glu(tamic acid) to val(ine).
7. The reason the text book says that this is the SIXTH amino acid instead of the seventh is because the beginning methionine is trimmed off as a part of post-translational modification when the protein is first made.

Now if you want to, you can make insertions and deletions to see how these types of mutations affect the production of a protein.

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© Copyright 2000 Department of Biology, Davidson College, Davidson, NC 28036
Send comments, questions, and suggestions to: macampbell@davidson.edu