7,8-didemethyl-8-hydroxy-5-deazariboflavin synthase (, ''FO synthase'') and 5-amino-6-(D-ribitylamino)uracil—L-tyrosine 4-hydroxyphenyl transferase () are two

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. A ...

s always complexed together to achieve synthesis of FO, a precursor to

Coenzyme F420 Coenzyme F420 or 8-hydroxy-5-deazaflavin is a coenzyme (sometimes called a cofactor) involved in redox reactions in methanogens, in many Actinomycetota, and sporadically in other bacterial lineages. It is a flavin derivative. The coenzyme is a ...

. Their

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

s are ''5-amino-5-(4-hydroxybenzyl)-6-(D-ribitylimino)-5,6-dihydrouracil ammonia-lyase (7,8-didemethyl-8-hydroxy-5-deazariboflavin-forming)'' and ''5-amino-6-(D-ribitylamino)uracil:L-tyrosine, 4-hydroxyphenyl transferase'' respectively. The enzymes

catalyse Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the following

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

s: : (2.5.1.147) 5-amino-6-(D-ribitylamino)uracil + L-

tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Gr ...

S-adenosyl-L-methionine ''S''-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throug ...

= 5-amino-5-(4-hydroxybenzyl)-6-(D-ribitylimino)-5,6-dihydrouracil + 2-iminoacetate + L-

methionine Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical ro ...

+ 5'-deoxyadenosin : (4.3.1.32) 5-amino-5-(4-hydroxybenzyl)-6-(D-ribitylimino)-5,6-dihydrouracil + S-adenosyl-L-methionine = 7,8-didemethyl-8-hydroxy-5-deazariboflavin + NH₃ + L-methionine + 5'-deoxyadenosine Enzyme 2.5.1.147 binds a 4Fe-4S cluster. The condensation reaction is initiated by the 5'-deoxyadenosyl radical. The complex was formerly named as a single entity under . All members of these enzymes belong to a single clade of the CofH (2.5.1.147) and CofG (4.3.1.32) families, sharing a

TIM barrel The TIM barrel (triose-phosphate isomerase), also known as an alpha/beta barrel, is a conserved protein fold consisting of eight alpha helices (α-helices) and eight parallel beta strands (β-strands) that alternate along the peptide backbone. ...

structure. The two EC numbers represent discrete steps in this reaction. Some enzyme complexes have CofG and CofH (subunits 1 and 2) in different chains assembled into a heterodimer, while others like the bifunctional ''fbiC'' has the two domains on one single chain.

References

External links

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