Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin. These proteins are involved in a wide array of biological processes, including removal of radicals contributing to oxidative stress, photosynthesis, and DNA repair. The flavoproteins are some of the most-studied families of enzymes.
Methionine synthase also known as MS, MeSe, MTR is responsible for the regeneration of methionine from homocysteine. In humans it is encoded by the MTR gene (5-methyltetrahydrofolate-homocysteine methyltransferase). Methionine synthase forms part of the S-adenosylmethionine (SAMe) biosynthesis and regeneration cycle, and is the enzyme responsible for linking the cycle to one-carbon metabolism via the folate cycle. There are two primary forms of this enzyme, the Vitamin B12 (cobalamin)-dependent (MetH) and independent (MetE) forms, although minimal core methionine synthases that do not fit cleanly into either category have also been described in some anaerobic bacteria. The two dominant forms of the enzymes appear to be evolutionary independent and rely on considerably different chemical mechanisms. Mammals and other higher eukaryotes express only the cobalamin-dependent form. In contrast, the distribution of the two forms in Archaeplastida (plants and algae) is more complex. Plants exclusively possess the cobalamin-independent form, while algae have either one of the two, depending on species. Many different microorganisms express both the cobalamin-dependent and cobalamin-independent forms.
In enzymology, a precorrin-6A reductase (EC 1.3.1.54) is an enzyme that catalyzes the chemical reaction
In enzymology, a precorrin-3B synthase (EC 1.14.13.83) is an enzyme that catalyzes the chemical reaction
[Methionine synthase] reductase, or Methionine synthase reductase, encoded by the gene MTRR, is an enzyme that is responsible for the reduction of methionine synthase inside human body. This enzyme is crucial for maintaining the one carbon metabolism, specifically the folate cycle. The enzyme employs one coenzyme, flavoprotein.
In enzymology, an FMN reductase (EC 1.5.1.29) is an enzyme that catalyzes the chemical reaction
In enzymology, a precorrin-8X methylmutase is an enzyme that catalyzes the chemical reaction
The enzyme threonine-phosphate decarboxylase (EC 4.1.1.81) catalyzes the chemical reaction
In enzymology, an adenosylcobyric acid synthase (glutamine-hydrolysing) (EC 6.3.5.10) is an enzyme that catalyzes the chemical reaction
Cobalt chelatase (EC 6.6.1.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a hydrogenobyrinic acid a,c-diamide synthase (glutamine-hydrolysing) (EC 6.3.5.9) is an enzyme that catalyzes the chemical reaction
In enzymology, a nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase is an enzyme that catalyzes the chemical reaction
Methionine synthase reductase, also known as MSR, is an enzyme that in humans is encoded by the MTRR gene.
Cob(I)yrinic acid a,c-diamide adenosyltransferase, mitochondrial is an enzyme that in humans is encoded by the MMAB gene.
Nitroreductases are a family of evolutionarily related proteins involved in the reduction of nitrogen-containing compounds, including those containing the nitro functional group. Members of this family utilise flavin mononucleotide as a cofactor and are often found to be homodimers.
In molecular biology, cob(I)yrinic acid a,c-diamide adenosyltransferase EC 2.5.1.17 is an enzyme which catalyses the conversion of cobalamin into one of its coenzyme forms, adenosylcobalamin. Adenosylcobalamin is required as a cofactor for the activity of certain enzymes. AdoCbl contains an adenosyl moiety liganded to the cobalt ion of cobalamin via a covalent Co-C bond.
Cobalamin biosynthesis is the process by which bacteria and archea make cobalamin, vitamin B12. Many steps are involved in converting aminolevulinic acid via uroporphyrinogen III and adenosylcobyric acid to the final forms in which it is used by enzymes in both the producing organisms and other species, including humans who acquire it through their diet.
5,6-dimethylbenzimidazole synthase (EC 1.14.99.40, BluB) is an enzyme with systematic name FMNH2 oxidoreductase (5,6-dimethylbenzimidazole forming). This enzyme catalyses the following chemical reaction
Cobalt-precorrin-5B (C1)-methyltransferase (EC 2.1.1.195), cobalt-precorrin-6A synthase, CbiD (gene)) is an enzyme with systematic name S-adenosyl-L-methionine:cobalt-precorrin-5B (C1)-methyltransferase. This enzyme catalyses the following chemical reaction
Morphinone reductase is an enzyme which catalyzes the NADH-dependent saturation of the carbon-carbon double bond of morphinone and codeinone, yielding hydromorphone and hydrocodone respectively. This saturation reaction is assisted by a FMN cofactor and the enzyme is a member of the α/β-barrel flavoprotein family. The sequence of the enzyme has been obtained from bacteria Pseudomonas putida M10 and has been successfully expressed in yeast and other bacterial species. The enzyme is reported to harbor high sequence and structural similarity to the Old Yellow Enzyme, a large group of flavin-dependent redox biocatalysts of yeast species, and an oestrogen-binding protein of Candida albicans. The enzyme has demonstrated value in biosynthesis of semi-opiate drugs in microorganisms, expanding the chemical diversity of BIA biosynthesis.
