The beta globin protein is one of the subunits of hemoglobin, a protein necessary for
the oxygen-carrying function of red blood cells
. People with the sickle cell mutation in both copies of the HBB gene produce proteins that clump together and lead to changes in the shape and behavior of red blood cells.
What is the function of globin in hemoglobin?
The globins are a superfamily of heme-containing globular proteins,
involved in binding and/or transporting oxygen
. These proteins all incorporate the globin fold, a series of eight alpha helical segments. Two prominent members include myoglobin and hemoglobin.
What are beta-globin chains?
Beta-globin is
a component (subunit) of a larger protein called hemoglobin
, which is located inside red blood cells. In adults, hemoglobin normally consists of four protein subunits: two subunits of beta-globin and two subunits of a protein called alpha-globin, which is produced from another gene called HBA.
What is beta-globin made of?
The entire beta-globin protein is
146 amino acids long
. It consists of 8 alpha helices – connected by turns – creating what is known as the “globin fold”. The beta-globin protein binds a heme group – a small molecule with an iron atom, that binds oxygen.
Where is beta-globin gene located?
The β-globin gene cluster occupies a
region of approximately 17 kb on the short arm of chromosome 11
. Each of its constituent genes, their flanking regions, and large stretches of the regions between them have been sequenced.
What is normal hemoglobin?
The normal range for hemoglobin is: For men,
13.5 to 17.5 grams per deciliter
. For women, 12.0 to 15.5 grams per deciliter.
What are two main components of hemoglobin?
Hemoglobin is a protein formed of two
subunits (alpha and beta)
that are found in red blood cells. The protein functions to pick up oxygen and distribute it throughout the body. Both the alpha and beta subunits need to be present for the acquisition of oxygen, as does an iron molecule.
Where is beta thalassemia most common?
Thousands of infants with beta thalassemia are born each year. Beta thalassemia occurs most frequently in people from
Mediterranean countries
, North Africa, the Middle East, India, Central Asia, and Southeast Asia.
What is the treatment for beta thalassemia?
Treatment may include:
Regular blood transfusions
.
Medicines to reduce extra iron from
your body (called iron chelation therapy) Surgery to remove the spleen, if needed.
What are the symptoms of beta thalassemia?
- tiredness.
- shortness of breath.
- a fast heartbeat.
- pale skin.
- yellow skin and eyes (jaundice)
- moodiness.
- slow growth.
Is valine an amino acid?
Valine, like other branched-chain amino acids, is synthesized by plants, but not by animals. It is therefore an
essential amino acid in animals
, and needs to be present in the diet.
How is the beta globin polypeptide produced?
HbS is produced by
a point mutation in HBB in which the codon GAG is replaced by GTG
. This results in the replacement of hydrophilic amino acid glutamic acid with the hydrophobic amino acid valine at the sixth position (β6Glu→Val).
What is the meaning of globin?
:
a colorless protein obtained by removal of heme from a conjugated protein and especially hemoglobin
.
How many human beta globin genes are there?
REGULATION OF THE B-GLOBIN GENE EXPRESSION. The human β-globin gene cluster consists of
five genes
arranged in chromosome 11 in the same order in which they are expressed during development: 5′-ɛ-, Gγ -, Aγ-, δ-, and β-globin gene (8) (Fig. 1).
How many beta globin genes are there?
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.
How many globin genes are there?
Since each cell has two chromosomes 16, a total of
four alpha globin genes
exist in each cell. Each of the four genes produces about one-quarter of the alpha globin chains needed for hemoglobin synthesis.
