Have a look at Molecular
scissors to find out more about restriction enzymes.
Below are the DNA sequences for part of the haemoglobin molecule
in humans, mice and horses.
Haemoglobin is a protein found in red blood cells that helps to
transport oxygen around the body.
Is haemoglobin the same in humans, mice and
horses?
The haemoglobin protein produced by this DNA performs the same
function in all three species. Do you think the number of
restriction enzyme recognition sites will be the same for all three
pieces of DNA?
Compare the different recognition sequences found in this piece
of DNA.
To do this, you can use an online DNA cutter. The website will
cut your DNA with all the common restriction enzymes known to
scientists.
Cut and paste each sequence into the empty white box on the DNA
cutter website. Then press submit.
Within a few seconds, the known restriction sites on that section
of DNA should be shown.
For each species, count the number of times these three
restriction enzymes appear in the list:
Are the numbers same or different for each species? Can you
think of a reason why the numbers might be different?
The DNA sequence for each haemoglobin molecule is below:
Human
ACATTTGCTTCTGACACAACTGTGTTCACTAGCAACCTCAAACAGACACCATGGTGCATCTGACTCCTGA
GGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAACGTGGATGAAGTTGGTGGTGAGGCCCTGGGC
AGGTTGGTATCAAGGTTACAAGACAGGTTTAAGGAGACCAATAGAAACTGGGCATGTGGAGACAGAGAAG
ACTCTTGGGTTTCTGATAGGCACTGACTCTCTCTGCCTATTGGTCTATTTTCCCACCCTTAGGCTGCTGG
TGGTCTACCCTTGGACCCAGAGGTTCTTTGAGTCCTTTGGGGATCTGTCCACTCCTGATGCTGTTATGGG
CAACCCTAAGGTGAAGGCTCATGGCAAGAAAGTGCTCGGTGCCTTTAGTGATGGCCTGGCTCACCTGGAC
AACCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACTGTGACAAGCTGCACGTGGATCCTGAGAACT
TCAGGGTGAGTCTATGGGACGCTTGATGTTTTCTTTCCCCTTCTTTTCTATGGTTAAGTTCATGTCATAG
GAAGGGGATAAGTAACAGGGTACAGTTTAGAATGGGAAACAGACGAATGATTGCATCAGTGTGGAAGTCT
CAGGATCGTTTTAGTTTCTTTTATTTGCTGTTCATAACAATTGTTTTCTTTTGTTTAATTCTTGCTTTCT
TTTTTTTTCTTCTCCGCAATTTTTACTATTATACTTAATGCCTTAACATTGTGTATAACAAAAGGAAATA
TCTCTGAGATACATTAAGTAACTTAAAAAAAAACTTTACACAGTCTGCCTAGTACATTACTATTTGGAAT
ATATGTGTGCTTATTTGCATATTCATAATCTCCCTACTTTATTTTCTTTTATTTTTAATTGATACATAAT
CATTATACATATTTATGGGTTAAAGTGTAATGTTTTAATATGTGTACACATATTGACCAAATCAGGGTAA
TTTTGCATTTGTAATTTTAAAAAATGCTTTCTTCTTTTAATATACTTTTTTGTTTATCTTATTTCTAATA
CTTTCCCTAATCTCTTTCTTTCAGGGCAATAATGATACAATGTATCATGCCTCTTTGCACCATTCTAAAG
AATAACAGTGATAATTTCTGGGTTAAGGCAATAGCAATATCTCTGCATATAAATATTTCTGCATATAAAT
TGTAACTGATGTAAGAGGTTTCATATTGCTAATAGCAGCTACAATCCAGCTACCATTCTGCTTTTATTTT
ATGGTTGGGATAAGGCTGGATTATTCTGAGTCCAAGCTAGGCCCTTTTGCTAATCATGTTCATACCTCTT
ATCTTCCTCCCACAGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCATCACTTTGGCAAAGAATTCA
CCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAATGCCCTGGCCCACAAGTATCA
CTAAGCTCGCTTTCTTGCTGTCCAATTTCTATTAAAGGTTCCTTTGTTCCCTAAGTCCAACTACTAAACT
GGGGGATATTATGAAGGGCCTTGAGCATCTGGATTCTGCCTAATAAAAAACATTTATTTTCATTGC
Mouse
TTACGTTTGCTTCTGATTCTGTTGTGTTGACTTGCAACCTCAGAAACAGACATCATGGTGCACCTGACTG
ATGCTGAGAAGGCTGCTGTCTCTGGCCTGTGGGGAAAGGTGAACGCCGATGAAGTTGGTGGTGAGGCCCT
GGGCAGGTTGGTATCCAGGTTACAAGGCAGCTCACAAGTAGAAGTTGGGTGCTTGGAGACAGAGGTCTGC
TTTCCAGCAGGCACTAACTTTGAGTGTCCCCTGTCTATGTTTCCCTTTTTAGGCTGCTGGTTGTCTACCC
TTGGACCCAGCGGTACTTTGATAGCTTTGGAGACCTATCCTCTGCCTCTGCTATCATGGGTAATGCCAAA
GTGAAGGCCCATGGCAAGAAAGTGATAACTGCCTTTAACGATGGCCTGAATCACTTGGACAGCCTCAAGG
GCACCTTTGCCAGCCTCAGTGAGCTCCACTGTGACAAGCTGCATGTGGATCCTGAGAACTTCAGGGTGAG
TCTGATGGGCACCTCCTGGGTTTCCTTCCCCTGGCTATTCTGCTCAACCTTCCTATCAGAAGGAAAGGGG
AAGCGATTCTAGGGAGCAGTCTCCATGACTGTGTGTGGAGTGTTGACAAGAGTTTGGATATTTTATTCTC
TACTCAGAATCGCTGCTCCCCCTCACTCTGTTCTGTGTTGTCATTTCCTCTTTCTTTGGTAAGCTTTTAA
TTTCCAGTTGCATTTTACTAAATTAATTAAGCTGGTTATTTACTTCCCATCCTGATATCAGCTTCCCCTC
CTCCTTTCCTCCCAGTCCTTCTCTCTCTCCTCTCTCTTTCTCTAATCCTTTCCTTTCCCTCAGTTCATTT
CTTCTTCTTTGATCTACTTTTGTTTGTCTTTTTAAATATTGCCTTGTAACTTACTCAGAGGACAAGGAAG
ATATGTCCCTGTTTCTTCTCATAGCTCTCAAGAATAGTAGCATAATTGGCTTTTATGCCAGGGTGACAGG
GGAAGAATATATTTTACATATAAATTCTGTTTGACATAGGATTCTTATAATAATTTGTCAGCAGTTTAAG
GTTGCAAACAAATGTCTTTATAAATAAGCCTGCAGTATCTGGTATTTTTGCTCTACAGTTATGTTGATGG
TTCTTCCATCTTCCCACAGCTCCTGGGCAATATGATCGTGATTGTGCTGGGCCACCACCTGGGCAAGGAT
TTCACCCCCGCTGCACAGGCTGCCTTCCAGAAGGTGGTGGCTGGAGTGGCTGCTGCCCTGGCTCACAAGT
ACCACTAAGCCCCTTTTCTGCTATTGTCTATGCACAAAGGTTATATGTCCCCTAGAGAAAAACTGTCAAT
TGTGGGGAAATGATGAAGACCTTTGGGCATCTAGCTTTTATCTAATAAATGATATTTACTGTCATC
Horse
ATGGTGCAACTGAGTGGTGAAGAGAAGGCAGCTGTCTTGGCCCTGTGGGACAAGGTGAATGAGGAAGAAG
TTGGTGGTGAAGCCCTGGGCAGGTTAGTATCCAGGATACAAGCAGCTTAAGGAGAGTCGTAGAAGCTGGG
TATGTGAATATACGACCGTCTCCTGGGTTTCTGACAGGTACTGACTGCCTCTGTCTCTTGTGCTGTTTAA
AACCTCTTAGGCTGCTGGTTGTCTACCCATGGACTCAGAGGTTCTTTGACTCCTTTGGGGATCTGTCCAA
TCCTGGTGCTGTGATGGGCAACCCCAAGGTGAAGGCCCACGGCAAGAAAGTGCTACACTCCTTTGGTGAG
GGCGTGCATCATCTTGACAACCTCAAGGGCACCTTTGCTGCGCTGAGTGAGCTGCACTGTGACAAGCTGC
ACGTGGATCCTGAGAACTTCAGGGTGAGTCTCTGTGACCCTCAATTTCTCCTTTGCCTTCCTCTTTTTGG
TCAAGCTCATGTAATGAGGAGAGGACATGAAAGTCAGGCTGCAGTTCAGAATGTGAAGAGATGTTGTGGT
TGCATCACTGCGGACTCCGGAGGAACATTTAAGTTCTTTTATTTTCTTTGCTCAAAACCCTTGTTTCTGC
TGGTTCATTCTTGTTTTCCTCTTTTTGGTCTCTGCAATATCTTCTCATTGTATTTTTAATTAAATTTTTT
GAGTGTTTAATTAAAAACAACTTTCTTCTTTGAATCTACTTTCTTTTTAAAAAAAAAATTCATCTAATAC
TTTCTTTCCCTTGTCTCTAACTCTTTCTTTCAAAGCAAAAAGGATAACATGTATTATTGCTTCCTTTCAT
GGTTCTAAAGAATAACATAACAAGTTCTGGGTTAAGGCAGAAAGGGAGAGACATTTTTAAGTATAAATTC
AGGTTGTTATTAGCGGATTCACATAAATAGTAACATCCAAGATTCAGCTATTTTCCTGCTTATATTCTAG
GGCACAGCTTTGGATAAGATTGGAATATTCTGAGCCCAAGCTGCTTCCCTCTGCTAACCATGCCCCCTCT
TTTTTCTCTTCCCCACAGCTCCTGGGCAACGTGCTGGTTGTTGTGCTGGCTCGCCACTTTGGCAAGGATT
TCACCCCAGAGTTGCAGGCTTCCTATCAAAAGGTGGTGGCTGGTGTGGCCAATGCACTGGCCCACAAATA
CCACTGA
By Zara Mahmoud, ScienceBuz