Selenoprotein

<p>In <a href="/facts/Molecular_biology/YgqU35ub">molecular biology</a>, a selenoprotein is any <a href="/facts/Protein/Jxmagu3E">protein</a> that includes a <a href="/facts/Selenocysteine/9ovfzrXW">selenocysteine</a> (Sec, U, Se-Cys) <a href="/facts/Amino_acid/WDxYwBny">amino acid</a> residue.  Among functionally characterized selenoproteins are five <a href="/facts/Glutathione_peroxidase/Y7AQpAub">glutathione peroxidases</a> (GPX) and three <a href="/facts/Thioredoxin_reductase/WD4BSDxj">thioredoxin reductases</a>, (TrxR/TXNRD) which both contain only one Sec. <a href="/facts/Selenoprotein_P/QFJC4Tow">Selenoprotein P</a> is the most common selenoprotein found in the plasma.  It is unusual because in humans it contains 10 Sec residues, which are split into two domains, a longer N-terminal domain that contains 1 Sec, and a shorter C-terminal domain that contains 9 Sec.  The longer N-terminal domain is likely an enzymatic domain, and the shorter C-terminal domain is likely a means of safely transporting the very reactive <a href="/facts/Selenium/k975NApC">selenium</a> atom throughout the body.
</p>

Selenoprotein open-in-new

Selenoprotein