ALAS1

ALAS1 or 5-aminolevulinate synthase 1 is an enzyme that in humans is encoded by the ALAS1 gene. It is a protein that is involved in the production of heme, a vital component of hemoglobin, the protein in red blood cells that carries oxygen.

Function

ALAS1 is the first enzyme in the heme biosynthetic pathway and it catalyzes the condensation of glycine and succinyl-CoA to form delta-aminolevulinic acid. This reaction is the rate-limiting step in the heme synthesis pathway.

Clinical significance

Mutations in the ALAS1 gene can lead to a variety of medical conditions. For example, a deficiency in ALAS1 can cause X-linked sideroblastic anemia, a rare disorder characterized by anemia and an excess of iron in the mitochondria of red blood cells.

Structure

The ALAS1 protein is a homodimer, meaning it is composed of two identical subunits. Each subunit contains a pyridoxal phosphate (PLP) binding site, which is essential for the enzyme's function.

See also

• ALAS2
• Heme synthesis
• X-linked sideroblastic anemia