Download Beta Globin and Mutations

Beta Globin and Mutations
Alexandra Childs and Ryan Edwards
Beta Globin
• Chromosome position: 11p15.5
• DNA nucleotides position: 5246696..5248301
• To the left of this gene in HBD or Delta globin
and to the right of this gene is OR51v1 or
Olfactory Receptor
HBB Location
• http://ghr.nlm.nih.gov/gene=HBB
Sequence of Beta Globin
Green: introns
Red: exons
Blue: Everything that is transcribed but non-coding
Mature mRNA and Translated protein
Sequence
•
Nucleotide Sequence (444 nt):
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAACGTGGATGAAG
TTGGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTACCCTTGGACCCAGAGGTTCTTTGAGTCCTTTGG
GGATCTGTCCACTCCTGATGCTGTTATGGGCAACCCTAAGGTGAAGGCTCATGGCAAGAAAGTGCTCGGT
GCCTTTAGTGATGGCCTGGCTCACCTGGACAACCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACT
GTGACAAGCTGCACGTGGATCCTGAGAACTTCAGGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCA
TCACTTTGGCAAAGAATTCACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAAT
GCCCTGGCCCACAAGTATCACTAA
Translation (147 aa):
MVHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKVKAHGKKVLG
AFSDGLAHLDNLKGTFATLSELHCDKLHVDPENFRLLGNVLVCVLAHHFGKEFTPPVQAAYQKVVAGVAN
ALAHKYH
Beta Globin Mutations
•
•
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Shepherd’s Bush
Hb Mainz
M Saskatoon
Thalassemia Mutation on the Initiation Codon
ATG to ATA
• Hb Rocky Mountain
Shepherd’s Bush
Gly and Asp
Aspartic Acid
Glycine
→
SB Mutated Sequence
•
Mutated Nucleotide Sequence (444 nt):
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAACGTGGATGAAG
TTGGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTACCCTTGGACCCAGAGGTTCTTTGAGTCCTTTGG
GGATCTGTCCACTCCTGATGCTGTTATGGGCAACCCTAAGGTGAAGGCTCATGGCAAGAAAGTGCTCGGT
GCCTTTAGTGATGACCTGGCTCACCTGGACAACCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACT
GTGACAAGCTGCACGTGGATCCTGAGAACTTCAGGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCA
TCACTTTGGCAAAGAATTCACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAAT
GCCCTGGCCCACAAGTATCACTAA
Mutated Translation (147 aa):
MVHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKVKAHGKKVLG
AFSDALAHLDNLKGTFATLSELHCDKLHVDPENFRLLGNVLVCVLAHHFGKEFTPPVQAAYQKVVAGVAN
ALAHKYH
Shepherds Bush Changes to
Protein
Shepherds Bush Physical Signs
• According to the variant database, this
mutation manifests itself as an increase in
oxygen affinity. It also results in a decreased
bpg (2,3-dpg).
• Moreover, the mutation causes the
hemoglobin to be unstable and hemolytic
anemia
Schematic Diagram of Hb-Mainz
Val and Glu
Valine
Glutamic Acid

Hb-Mainz Mutated Sequence
•
Mutated Nucleotide Sequence (444 nt):
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAACGTGGATGAAG
TTGGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTACCCTTGGACCCAGAGGTTCTTTGAGTCCTTTGG
GGATCTGTCCACTCCTGATGCTGTTATGGGCAACCCTAAGGTGAAGGCTCATGGCAAGAAAGTGCTCGGT
GCCTTTAGTGATGACCTGGCTCACCTGGACAACCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACT
GTGACAAGCTGCACGAGGATCCTGAGAACTTCAGGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCA
TCACTTTGGCAAAGAATTCACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAAT
GCCCTGGCCCACAAGTATCACTAA
Mutated Translation (147 aa):
MVHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKVKAHGKKVLG
AFSDALAHLDNLKGTFATLSELHCDKLHEDPENFRLLGNVLVCVLAHHFGKEFTPPVQAAYQKVVAGVAN
ALAHKYH
Hb-Mainz Changes to Protein
Hb-Mainz Physical Effects
• According to the variant database, Hb-Mainz
causes hemoglobin to become unstable and
also causes hemolytic severe anemia.
Hb M-Saskatoon Mutation
M-Saskatoon Detailed Sequence
•
•
(Mutated) Nucleotide Sequence (444 nt):
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAAC
GTGGATGAAGTTGGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTACCCTTGGACCCAG
AGGTTCTTTGAGTCCTTTGGGGATCTGTCCACTCCTGATGCTGTTATGGGCAACCCTAAGGT
GAAGGCTTATGGCAAGAAAGTGCTCGGTGCCTTTAGTGATGGCCTGGCTCACCTGGACAA
CCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACTGTGACAAGCTGCACGTGGATCC
TGAGAACTTCAGGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCATCACTTTGGCAAA
GAATTCACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAATGCCC
TGGCCCACAAGTATCACTAA
(Mutated) Translation (147 aa):
MVHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKV
KAYGKKVLGAFSDGLAHLDNLKGTFATLSELHCDKLHVDPENFRLLGNVLVCVLAHHFGKEFTP
PVQAAYQKVVAGVANALAHKYH
CAT becomes TAT
H becomes Y
Amino Acid Change
Histidine
Tyrosine
→
3D Protein Sequence of
Hemoglobin
Histidine is a positively charged
hydrophilic amino acid
Tyrosine is an uncharged hydrophilic
amino acid
What do you notice about where this
mutation is near to?
We will come back to this…
M-Saskatoon, Methemoglobinemia
• Special class of low O2
affinity hemoglobin variant
• Iron in the heme is in an
abnormal oxidation state
• Known as methemoglobin.
– useless in O2 binding.
• Has a brown pigment
• Causes cyanosis
• Mutation may also cause
Dissociation of Dimers
Thalassemias Mutation of Initiation
Codon ATG -> ATA beta0
•
•
•
•
•
•
(Original) Nucleotide Sequence (444 nt):
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAACGTGGATGAAGTT
GGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTACCCTTGGACCCAGAGGTTCTTTGAGTCCTTTGGGGAT
CTGTCCACTCCTGATGCTGTTATGGGCAACCCTAAGGTGAAGGCTCATGGCAAGAAAGTGCTCGGTGCCTTTA
GTGATGGCCTGGCTCACCTGGACAACCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACTGTGACAAGCT
GCACGTGGATCCTGAGAACTTCAGGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCATCACTTTGGCAAA
GAATTCACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAATGCCCTGGCCCACAAGT
ATCACTAA
(Original) Translation (147 aa):
MVHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKVKAHGKKVLGAFS
DGLAHLDNLKGTFATLSELHCDKLHVDPENFRLLGNVLVCVLAHHFGKEFTPPVQAAYQKVVAGVANALAHKYH
RED – Initiation Codon that changes to ATA which no longer begins the reading frame
Blue- Region of nucleotide base pairings, amino acids, and protein that is not read because of the
mutation to the START codon
Orange- Codon which becomes the START codon but originally is split into two codons before the
mutation. All subsequent amino acids change in the translation
Green- New Stop Codon
Amino Acid Change
Methionine
Isoleucine
→
New Sequence Details
• (Mutated) Nucleotide Sequence (444 nt):
ATGAAGTTGGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTA
CCCTTGGACCCAGAGGTTCTTTGAGTCCTTTGGGGATCTGTCCA
CTCCTGATGCTGTTATGGGCAACCCTAAGGTGAAGGCTCATGGC
AAGAAAGTGCTCGGTGCCTTTAGTGATGGCCTGGCTCACCTGG
ACAACCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACTG
TGACAAGCTGCACGTGGATCCTGAGAACTTCAGGCTCCTGGGC
AACGTGCTGGTCTGTGTGCTGGCCCATCACTTTGGCAAAGAATT
CACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGT
GTGGCTAATGCCCTGGCCCACAAGTATCACTAA
• (Mutated) Translation (aa):
MKLVVRPWAGCWWSTLGPRGSLSPLGICPLLMLLWATLR(STOP)
Hb Rocky Mountain
Sequence Detail of Hb Rocky Mountain
•
•
(Mutated)Nucleotide Sequence (444 nt):
ATGGTGCATCTGACTCCTGAGGAGAAGTCTGCCGTTACTGCCCTGTGGGGCAAGGTGAAC
GTGGTTGAAGTTGGTGGTGAGGCCCTGGGCAGGCTGCTGGTGGTCTACCCTTGGACCCAG
AGGTTCTTTGAGTCCTTTGGGGATCTGTCCACTCCTGATGCTGTTATGGGCAACCCTAAGGT
GAAGGCTCATGGCAAGAAAGTGCTCGGTGCCTTTAGTGATGGCCTGGCTCACCTGGACAA
CCTCAAGGGCACCTTTGCCACACTGAGTGAGCTGCACTGTGACAAGCTGCACGTGGATCC
TGAGAACTTCAGGCTCCTGGGCAACGTGCTGGTCTGTGTGCTGGCCCATCACTTTGGCAAA
GAATTCACCCCACCAGTGCAGGCTGCCTATCAGAAAGTGGTGGCTGGTGTGGCTAATGCCC
TGGCCCACAAGTATCACTAA
(Original)Translation (147 aa):
MVHLTPEEKSAVTALWGKVNVVEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKV
KAHGKKVLGAFSDGLAHLDNLKGTFATLSELHCDKLHVDPENFRLLGNVLVCVLAHHFGKEFT
PPVQAAYQKVVAGVANALAHKYH
GAT becomes GTT
Aspartic Acid (D) becomes Valine (V)
Amino Acid Change
Aspartic Acid
Valine
→
Protein Structure and Description of
Effects of Mutation
• Aspartic Acid is
hydrophilic and negatively
charged polar
• Valine is hydrophobic and
non polar making it mildly
unstable
• The change in the protein
sequence may affect Hb
function in cells as it
causes an alteration in
the protein shape
Effects of Hb Rocky Mountain
• Those with an Hb Rocky Mountain mutation
(a.k.a. Hb Paddington) develop Microcytosis
• Smaller red blood cells
• Those with mutation are at higher risk of
being anemic
• Why do you think that is if the red blood cell
count is the same as a healthy person?
Useful Sites for Sheperds Bush/
Biblography
• http://globin.bx.psu.edu/cgibin/hbvar/query_vars3?mode=output&display_f
ormat=page&i=387
• http://globin.cse.psu.edu/html/huisman/variants
/beta/Shepherds.Bush.html
• http://books.google.com/books?id=H85dwxYTKL
wC&lpg=RA1PA1623&ots=A9ufCRxiMW&dq=Shepherds%20Bu
sh%20mutat&pg=RA1PA1623#v=onepage&q=shepherds%20bush&f=fal
se
Sources for Hb-Mainz
• http://www.umm.edu/blood/anehemol.htm
• http://globin.bx.psu.edu/cgibin/hbvar/query_vars3?mode=output&displa
y_format=page&i=451
• http://www.ncbi.nlm.nih.gov/pubmed/17356
397
Useful Sites of Hb Rocky Mountain
• http://globin.bx.psu.edu/cgibin/hbvar/query_vars3?mode=output&displa
y_format=page&i=925
• http://www.pdb.org/pdb/explore/jmol.do?str
uctureId=2HHB&bionumber=1
• http://en.wikipedia.org/wiki/Mean_corpuscul
ar_volume
• http://en.wikipedia.org/wiki/Microcytosis
Sites On Hb M-Saskatoon
• http://web2.airmail.net/uthman/hemoglobin
opathy/hemoglobinopathy.html
• http://www.ncbi.nlm.nih.gov/pubmed/76630
00
• http://globin.bx.psu.edu/cgibin/hbvar/query_vars3?mode=output&displa
y_format=page&i=359