Hemoglobin subunit alpha, Hemoglobin, alpha 1,
is a
hemoglobin
Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyt ...
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
that in humans is encoded by the ''HBA1''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Gene
The human alpha globin
gene cluster
A gene family is a set of homologous genes within one organism. A gene cluster is a group of two or more genes found within an organism's DNA that encode similar polypeptides, or proteins, which collectively share a generalized function and are ...
located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (
HBA2
Hemoglobin, alpha 2 also known as HBA2 is a gene that in humans codes for the alpha globin chain of hemoglobin.
Function
The human alpha globin gene cluster is located on chromosome 16 and spans about 30 kb, including seven alpha like globin ...
) and alpha-1 (HBA1; this gene) coding sequences are identical. These genes differ slightly over the
5' untranslated regions and the
introns, but they differ significantly over the
3' untranslated regions.
Protein
Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total
hemoglobin
Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyt ...
; alpha chains combine with delta chains to constitute HbA-2, which with
fetal hemoglobin (HbF) makes up the remaining 3% of adult hemoglobin.
Clinical significance
Alpha
thalassemias result from deletions of each of the alpha genes as well as deletions of both
HBA2
Hemoglobin, alpha 2 also known as HBA2 is a gene that in humans codes for the alpha globin chain of hemoglobin.
Function
The human alpha globin gene cluster is located on chromosome 16 and spans about 30 kb, including seven alpha like globin ...
and
HBA1
Hemoglobin subunit alpha, Hemoglobin, alpha 1, is a hemoglobin protein that in humans is encoded by the ''HBA1'' gene.
Gene
The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseu ...
; some nondeletion alpha thalassemias have also been reported.
Interactions
Hemoglobin subunit alpha has been shown to
interact with
hemoglobin subunit beta
Hemoglobin subunit beta (beta globin, β-globin, haemoglobin beta, hemoglobin beta) is a globin protein, coded for by the ''HBB'' gene, which along with alpha globin ( HBA), makes up the most common form of haemoglobin in adult humans, hemogl ...
(HBB).
See also
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Hemoglobin subunit beta
Hemoglobin subunit beta (beta globin, β-globin, haemoglobin beta, hemoglobin beta) is a globin protein, coded for by the ''HBB'' gene, which along with alpha globin ( HBA), makes up the most common form of haemoglobin in adult humans, hemogl ...
*
Human β-globin locus The human β-globin locus is composed of five genes located on a short region of chromosome 11, responsible for the creation of the beta parts (roughly half) of the oxygen transport protein Haemoglobin. This locus contains not only the beta globin ...
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Alpha-Thalassemia OMIM entries on Alpha-Thalassemia*
Hemoglobins
{{DEFAULTSORT:Hemoglobin, alpha 1