UROS : uroporphyrinogen III synthase
Description
The UROS (uroporphyrinogen III synthase) is a protein-coding gene located on chromosome 10.
The UROS gene provides instructions for making an enzyme known as uroporphyrinogen III synthase. This enzyme is involved in the production of a molecule called heme. Heme is vital for all of the body's organs, although it is most abundant in the blood, bone marrow, and liver. Heme is an essential component of iron-containing proteins called hemoproteins, including hemoglobin (the protein that carries oxygen in the blood). The production of heme is a multi-step process that requires eight different enzymes. Uroporphyrinogen III synthase is responsible for the fourth step in this process, in which hydroxymethylbilane (the product of the third step) is rearranged to form uroporphyrinogen III. In subsequent steps, four other enzymes produce and modify compounds that ultimately lead to heme.
The UROS gene encodes for an enzyme, uroporphyrinogen III synthase (URO-S), which catalyzes the cyclization of the linear tetrapyrrole, hydroxymethylbilane, to the macrocyclic uroporphyrinogen III. This is a crucial step in the biosynthesis of porphyrins, a diverse group of molecules that act as cofactors for numerous enzymes involved in various cellular processes, including methionine synthesis (vitamin B12) and oxygen transport (heme).
UROS is also known as UROIIIS.
