Methanofurans are a family of

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

s found in

methanogen Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota. Methanogens are c ...

archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaeba ...

. These species feature a 2-aminomethyl

furan Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans. Furan is a colorless, flammable, highl ...

linked to

phenoxy In chemistry, the alkoxy group is an alkyl group which is singularly bonded to oxygen; thus . The range of alkoxy groups is vast, the simplest being methoxy (). An ethoxy group () is found in the organic compound ethyl phenyl ether (, also k ...

group. At least three different end groups are recognized: R = tricarboxyheptanoyl (methanofuran),

glutamyl Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synt ...

-glutamyl (methanofuran b), tricarboxy-2-hydroxyheptanoyl (methanofuran c, see picture).

Formylation of MFR

Methanofuran converts to

formylmethanofuran Methanofurans are a family of chemical compounds found in methanogenic archaea. These species feature a 2-aminomethylfuran linked to phenoxy group. At least three different end groups are recognized: R = tricarboxyheptanoyl (methanofuran), glu ...

in an early stage of

methanogenesis Methanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. Organisms capable of producing methane for energy conservation have been identified only from the domain Archaea, a group ...

. The enzyme formylmethanofuran dehydrogenase ( EC: 1.2.99.5) formylates methanofuran using , the primary C1 source in methanogenesis.

Deformylation of MFR

The

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

formylmethanofuran:tetrahydromethanopterin formyltransferase catalyzes the transfer of the formyl group from formylmethanofuran to N5 on

tetrahydromethanopterin Tetrahydromethanopterin (THMPT, ) is a coenzyme in methanogenesis. It is the carrier of the C1 group as it is reduced to the methyl level, before transferring to the coenzyme M. Tetrahydrosarcinapterin (THSPT, ) is a modified form of THMPT, wher ...

, . This enzyme has been crystallized; it contains no

prosthetic group A prosthetic group is the non-amino acid component that is part of the structure of the heteroproteins or conjugated proteins, being tightly linked to the apoprotein. Not to be confused with the cofactor that binds to the enzyme apoenzyme (eith ...

References

{{Enzyme cofactors Amines Peptides Coenzymes