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QuickView for pan troglodytes (biogroup)
- Description:
- Haptoglobin is a plasma protein that binds haemoglobin. The resulting complex is too large to be excreted by the kidney, thereby preventing loss of iron and damage to the kidney. The haptoglobin-haemoglobin complex is degraded in the liver, which is also the site of haptoglobin synthesis. The mature haptoglobin molecule is a tetramer, consisting of two alpha and two beta chains. Alpha and beta chains arise from proteolytic processing of the same precursor. Each beta chain can bind an alpha-beta heterodimer of haemoglobin so that each haptoglobin tetramer binds one haemoglobin tetramer. In Pan troglodytes (Chimpanzee), haptoglobin genes form a small multigene family of three genes: HP, HPR (haptoglobin-related protein, which may be non-functional), and HPP (haptoglobin-primate). In contrast, most humans have a two-gene cluster due to an unequal homologous crossover event between HPR and HPP in the human lineage. Such events may be common among these closely related genes as Macaca mulatta (Rhesus macaque) was found to have haplotypes of one- or two-gene clusters that appear to have formed from unequal crossover among an ancestral three-gene cluster. The haptoglobin precursor contains a signal sequence, a sushi domain (in mature alpha chain), and a trypsin domain (in mature beta chain) which belongs to the MEROPS peptidase family S1 (clan PA(S)). Haptoglobins have no enzymatic activity as the active site residues typical of trypsin-related proteases are not conserved, they are therefore classed as non-peptidase homologues. A common allelic variant in humans contains two sushi domains.
- Taxonomy/Path:
- InterPro : Peptidase S1A, chymotrypsin family / Haptoglobin
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