Structure and Genetics
Most types of normal hemoglobin, including hemoglobin A, hemoglobin A2, and hemoglobin F, are tetramers composed of four protein subunits and four heme prosthetic groups. Whereas adult hemoglobin is composed of two alpha and two beta subunits, fetal hemoglobin is composed of two alpha and two gamma subunits, commonly denoted as α2γ2. Because of its presence in fetal hemoglobin, the gamma subunit is commonly called the "fetal" hemoglobin subunit.
In humans, each chromosome 11 contains two similar copies of the gene that encodes the gamma subunit, γG (glycine as residue 136) and γA (alanine as residue 136). (The beta subunit is also on Chromosome 11) The gene that codes for the alpha subunit is located on chromosome 16 and is also present in duplicate.
Read more about this topic: Fetal Hemoglobin
Famous quotes containing the words structure and and/or structure:
“Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other—only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.”
—Talcott Parsons (1902–1979)
“What is the structure of government that will best guard against the precipitate counsels and factious combinations for unjust purposes, without a sacrifice of the fundamental principle of republicanism?”
—James Madison (1751–1836)