Flavoprotein

Flavoproteins are <a href="/facts/Proteins/Jxmagu3E">proteins</a> that contain a <a href="/facts/Nucleic_acid/2tTgcI0v">nucleic acid</a> derivative of <a href="/facts/Riboflavin/M8D8EbmD">riboflavin</a>. These proteins are involved in a wide array of biological processes, including removal of <a href="/facts/Radical_(chemistry)/qFymuVoT">radicals</a> contributing to oxidative stress, <a href="/facts/Photosynthesis/TMV7w693">photosynthesis</a>, and <a href="/facts/DNA_repair/hsURuYYq">DNA repair</a>. The flavoproteins are some of the most-studied families of enzymes.
Flavoproteins have either FMN (<a href="/facts/Flavin_mononucleotide/cWutCJmR">flavin mononucleotide</a>) or FAD (<a href="/facts/Flavin_adenine_dinucleotide/uzADx3ES">flavin adenine dinucleotide</a>) as a prosthetic group or as a <a href="/facts/Cofactor_(biochemistry)/AGo0PCUU">cofactor</a>. The flavin is generally tightly bound (as in <a href="/facts/Adrenodoxin_reductase/g5WzhCpc">adrenodoxin reductase</a>, wherein the FAD is buried deeply). About 5-10% of flavoproteins have a covalently linked FAD. Based on the available structural data, FAD-binding sites can be divided into more than 200 different types.
90 flavoproteins are encoded in the human genome; about 84% require FAD and around 16% require FMN, whereas 5 proteins require both. Flavoproteins are mainly located in the <a href="/facts/Mitochondria/ErHqrdJ1">mitochondria</a>. Of all flavoproteins, 90% perform redox reactions and the other 10% are <a href="/facts/Transferases/ut43BDxU">transferases</a>, <a href="/facts/Lyases/Ll2jFfhU">lyases</a>, <a href="/facts/Isomerases/DtUWnvle">isomerases</a>, <a href="/facts/Ligases/cnwMmUln">ligases</a>.

Flavoprotein open-in-new

Flavoprotein