Browsing Pathways

Dihydrofolic acid, a product of the folate biosynthesis pathway, can be metabolized by multiple enzymes. Dihydrofolic acid can be reduced by a NADP-driven dihydrofolate reductase resulting in a NADPH, hydrogen ion and folic acid. Dihydrofolic acid can also be reduced by an NADPH-driven dihydrofolate reductase resulting in a NADP and a tetrahydrofolic acid. Folic acid can also produce a tetrahydrofolic acid through a NADPH-driven dihydrofolate reductase. Dihydrofolic acid also interacts with 5-thymidylic acid through a thymidylate synthase resulting in the release of dUMP and 5,10-methylene-THF Tetrahydrofolic acid can be converted into 5,10-methylene-THF through two different reversible reactions. Tetrahydrofolic acid interacts with a S-Aminomethyldihydrolipoylprotein through a aminomethyltransferase resulting in the release of ammonia, a dihydrolipoylprotein and 5,10-Methylene-THF Tetrahydrofolic acid interacts with L-serine through a glycine hydroxymethyltransferase resulting in a glycine, water and 5,10-Methylene-THF. The compound 5,10-methylene-THF reacts with an NADPH dependent methylenetetrahydrofolate reductase [NAD(P)H] resulting in NADP and 5-Methyltetrahydrofolic acid. This compound interacts with homocysteine through a methionine synthase resulting in L-methionine and tetrahydrofolic acid. Tetrahydrofolic acid can be metabolized into 10-formyltetrahydrofolate through 4 different enzymes: 1.- Tetrahydrofolic acid interacts with FAICAR through a phosphoribosylaminoimidazolecarboxamide formyltransferase resulting in a 1-(5'-Phosphoribosyl)-5-amino-4-imidazolecarboxamide and a 10-formyltetrahydrofolate 2.-Tetrahydrofolic acid interacts with 5'-Phosphoribosyl-N-formylglycinamide through a phosphoribosylglycinamide formyltransferase 2 resulting in a Glycineamideribotide and a 10-formyltetrahydrofolate 3.-Tetrahydrofolic acid interacts with Formic acid through a formyltetrahydrofolate hydrolase resulting in water and a 10-formyltetrahydrofolate 4.-Tetrahydrofolic acid interacts with N-formylmethionyl-tRNA(fMet) through a 10-formyltetrahydrofolate:L-methionyl-tRNA(fMet) N-formyltransferase resulting in a L-methionyl-tRNA(Met) and a 10-formyltetrahydrofolate 10-formyltetrahydrofolate can interact with a hydrogen ion through a bifunctional 5,10-methylene-tetrahydrofolate dehydrogenase resulting in water and 5,10-methenyltetrahydrofolic acid. Tetrahydrofolic acid can be metabolized into 5,10-methenyltetrahydrofolic acid by reacting with a 5'-phosphoribosyl-a-N-formylglycineamidine through a phosphoribosylglycinamide formyltransferase 2 resulting in water, glycineamideribotide and 5,10-methenyltetrahydrofolic acid. The latter compound can either interact with water through an aminomethyltransferase resulting in a N5-Formyl-THF, or it can interact with a NADPH driven bifunctional 5,10-methylene-tetrahydrofolate dehydrogenase resulting in a NADP and 5,10-Methylene THF.

Dihydrofolic acid, a product of the folate biosynthesis pathway, can be metabolized by multiple enzymes. Dihydrofolic acid can be reduced by a NADP-driven dihydrofolate reductase resulting in a NADPH, hydrogen ion and folic acid. Dihydrofolic acid can also be reduced by an NADPH-driven dihydrofolate reductase resulting in a NADP and a tetrahydrofolic acid. Folic acid can also produce a tetrahydrofolic acid through a NADPH-driven dihydrofolate reductase. Dihydrofolic acid also interacts with 5-thymidylic acid through a thymidylate synthase resulting in the release of dUMP and 5,10-methylene-THF Tetrahydrofolic acid can be converted into 5,10-methylene-THF through two different reversible reactions. Tetrahydrofolic acid interacts with a S-Aminomethyldihydrolipoylprotein through a aminomethyltransferase resulting in the release of ammonia, a dihydrolipoylprotein and 5,10-Methylene-THF Tetrahydrofolic acid interacts with L-serine through a glycine hydroxymethyltransferase resulting in a glycine, water and 5,10-Methylene-THF. The compound 5,10-methylene-THF reacts with an NADPH dependent methylenetetrahydrofolate reductase [NAD(P)H] resulting in NADP and 5-Methyltetrahydrofolic acid. This compound interacts with homocysteine through a methionine synthase resulting in L-methionine and tetrahydrofolic acid. Tetrahydrofolic acid can be metabolized into 10-formyltetrahydrofolate through 4 different enzymes: 1.- Tetrahydrofolic acid interacts with FAICAR through a phosphoribosylaminoimidazolecarboxamide formyltransferase resulting in a 1-(5'-Phosphoribosyl)-5-amino-4-imidazolecarboxamide and a 10-formyltetrahydrofolate 2.-Tetrahydrofolic acid interacts with 5'-Phosphoribosyl-N-formylglycinamide through a phosphoribosylglycinamide formyltransferase 2 resulting in a Glycineamideribotide and a 10-formyltetrahydrofolate 3.-Tetrahydrofolic acid interacts with Formic acid through a formyltetrahydrofolate hydrolase resulting in water and a 10-formyltetrahydrofolate 4.-Tetrahydrofolic acid interacts with N-formylmethionyl-tRNA(fMet) through a 10-formyltetrahydrofolate:L-methionyl-tRNA(fMet) N-formyltransferase resulting in a L-methionyl-tRNA(Met) and a 10-formyltetrahydrofolate 10-formyltetrahydrofolate can interact with a hydrogen ion through a bifunctional 5,10-methylene-tetrahydrofolate dehydrogenase resulting in water and 5,10-methenyltetrahydrofolic acid. Tetrahydrofolic acid can be metabolized into 5,10-methenyltetrahydrofolic acid by reacting with a 5'-phosphoribosyl-a-N-formylglycineamidine through a phosphoribosylglycinamide formyltransferase 2 resulting in water, glycineamideribotide and 5,10-methenyltetrahydrofolic acid. The latter compound can either interact with water through an aminomethyltransferase resulting in a N5-Formyl-THF, or it can interact with a NADPH driven bifunctional 5,10-methylene-tetrahydrofolate dehydrogenase resulting in a NADP and 5,10-Methylene THF.

Methylglyoxal, also known as pyruvaldehyde, is a cytotoxic compound derived from pyruvic acid. In E. coli, there are at least eight pathways that are responsible for the detoxification of methylglyoxal. The first reaction in this pathway is the reduction of pyruvaldehyde to (S)-lactaldehyde, along with the cofactor NADH, catalyzed by 2,5-diketo-D-gluconic acid reductase subunits A and B. Following this, (S)-lactaldehyde is dehydrogenated into L-lactic acid by the lactaldehyde dehydrogenase enzyme, also using NAD as a cofactor. Finally, L-lactic acid is converted to pyruvic acid by L-lactate dehydrogenase in a reaction involving the reduction of an electron acceptor. Pyruvic acid is then used in glycolysis and pyruvate dehydrogenase pathways.

Methylglyoxal, also known as pyruvaldehyde, is a cytotoxic compound derived from pyruvic acid. In E. coli, there are at least eight pathways that are responsible for the detoxification of methylglyoxal. The first reaction in this pathway is the reversible reduction of pyruvaldehyde to hydroxyacetone, along with the cofactor NADPH, catalyzed by an uncharacterized protein encoded by the yghZ gene, now known to be L-glyceraldehyde 3-phosphate reductase. Following this, hydroxyacetone is oxidized into (S)-propane-1,2-diol by the glycerol dehydrogenase enzyme, using NAD as a cofactor. Finally, (S)-propane-1,2-diol is transported into the periplasmic space.

Methylglyoxal, also known as pyruvaldehyde, is a cytotoxic compound derived from pyruvic acid. In E. coli, there are at least eight pathways that are responsible for the detoxification of methylglyoxal. The first reaction in this pathway is the reversible reduction of pyruvaldehyde to hydroxyacetone, along with the cofactor NADPH, catalyzed by an uncharacterized protein encoded by the yghZ gene, now known to be L-glyceraldehyde 3-phosphate reductase. Following this, hydroxyacetone is oxidized into (S)-propane-1,2-diol by the glycerol dehydrogenase enzyme, using NAD as a cofactor. Finally, (S)-propane-1,2-diol is transported into the periplasmic space.

L-lyxose is a sugar and a monosaccharide containing five carbon atoms and aldehyde group. Wild-type E.coli can't utilize L-lyxose as its source of carbon and energy. In mutated E.coli, it can metabolize l-lyxose through utilization of enzymes of the rhamnose, arabinose and 2,3-diketo-L-gulonate systems. β-L-lyxopyranose enter cell by L-rhamnose-proton symporter, then convert to l-xylulose by L-rhamnose isomerase. L-xylulose is further metabolized to L-xylulose-5-phosphate with energy ATP. Putative L-ribulose-5-phosphate 3-epimerase can convert L-xylulose -5-phosphate to L-ribulose 5-phosphate, and L-ribulose 5-phosphate 4-epimerase can catalyze L-ribulose 5-phosphate to xylulose 5-phosphate for further pentose phosphate.

Methylglyoxal, also known as pyruvaldehyde, is a cytotoxic compound derived from pyruvic acid. In E. coli, there are at least eight pathways that are responsible for the detoxification of methylglyoxal. The first reaction in this pathway is the reversible reduction of pyruvaldehyde to hydroxyacetone, along with the cofactor NADPH, catalyzed by an uncharacterized protein encoded by the yghZ gene, now known to be L-glyceraldehyde 3-phosphate reductase. Following this, hydroxyacetone is oxidized into (S)-propane-1,2-diol by the glycerol dehydrogenase enzyme, using NAD as a cofactor. Finally, (S)-propane-1,2-diol is transported into the periplasmic space.

The most common pathway for methylglyoxal detoxification is the glyoxalase system, which is composed of two enzymes that together convert methylglyoxal to (R)-lactate in the presence of glutathione. However, in E. coli, a single enzyme, glyoxalase III, catalyzes this conversion in a single step without involvement of glutathione. Activity of glyoxalase III increases at the transition to stationary phase and expression is dependent on RpoS, suggesting that this pathway may be important during stationary phase. (EcoCyc)

Methylglyoxal, also known as pyruvaldehyde, is a cytotoxic compound derived from pyruvic acid. In E. coli, there are at least eight pathways that are responsible for the detoxification of methylglyoxal. The first reaction in this pathway is the reduction of pyruvaldehyde to (S)-lactaldehyde, along with the cofactor NADH, catalyzed by 2,5-diketo-D-gluconic acid reductase subunits A and B. Following this, (S)-lactaldehyde is dehydrogenated into L-lactic acid by the lactaldehyde dehydrogenase enzyme, also using NAD as a cofactor. Finally, L-lactic acid is converted to pyruvic acid by L-lactate dehydrogenase in a reaction involving the reduction of an electron acceptor. Pyruvic acid is then used in glycolysis and pyruvate dehydrogenase pathways.