Thymidine phosphorylase; The enzymes which catalyze the reversible phosphorolysis of pyrimidine nucleosides are involved in the degradation of these compounds and in their utilization as carbon and energy sources, or in the rescue of pyrimidine bases for nucleotide synthesis; Belongs to the thymidine/pyrimidine-nucleoside phosphorylase family.

Thymidine kinase/deoxyuridine kinase; Phosphorylates both thymidine and deoxyuridine.

Thymidine phosphorylase; The enzymes which catalyze the reversible phosphorolysis of pyrimidine nucleosides are involved in the degradation of these compounds and in their utilization as carbon and energy sources, or in the rescue of pyrimidine bases for nucleotide synthesis; Belongs to the thymidine/pyrimidine-nucleoside phosphorylase family.

Thymidylate synthetase; Catalyzes the reductive methylation of 2'-deoxyuridine-5'- monophosphate (dUMP) to 2'-deoxythymidine-5'-monophosphate (dTMP) while utilizing 5,10-methylenetetrahydrofolate (mTHF) as the methyl donor and reductant in the reaction, yielding dihydrofolate (DHF) as a by-product. This enzymatic reaction provides an intracellular de novo source of dTMP, an essential precursor for DNA biosynthesis. This protein also binds to its mRNA thus repressing its own translation.

Thymidine phosphorylase; The enzymes which catalyze the reversible phosphorolysis of pyrimidine nucleosides are involved in the degradation of these compounds and in their utilization as carbon and energy sources, or in the rescue of pyrimidine bases for nucleotide synthesis; Belongs to the thymidine/pyrimidine-nucleoside phosphorylase family.

Thymidylate kinase; Catalyzes the reversible phosphorylation of deoxythymidine monophosphate (dTMP) to deoxythymidine diphosphate (dTDP), using ATP as its preferred phosphoryl donor. Situated at the junction of both de novo and salvage pathways of deoxythymidine triphosphate (dTTP) synthesis, is essential for DNA synthesis and cellular growth; Belongs to the thymidylate kinase family.

Thymidine phosphorylase; The enzymes which catalyze the reversible phosphorolysis of pyrimidine nucleosides are involved in the degradation of these compounds and in their utilization as carbon and energy sources, or in the rescue of pyrimidine bases for nucleotide synthesis; Belongs to the thymidine/pyrimidine-nucleoside phosphorylase family.

Uridine/cytidine kinase; Protein involved in nucleobase, nucleoside and nucleotide interconversion; Belongs to the uridine kinase family.

Thymidine phosphorylase; The enzymes which catalyze the reversible phosphorolysis of pyrimidine nucleosides are involved in the degradation of these compounds and in their utilization as carbon and energy sources, or in the rescue of pyrimidine bases for nucleotide synthesis; Belongs to the thymidine/pyrimidine-nucleoside phosphorylase family.

Uridine phosphorylase; Catalyzes the reversible phosphorylytic cleavage of uridine and deoxyuridine to uracil and ribose- or deoxyribose-1-phosphate. The produced molecules are then utilized as carbon and energy sources or in the rescue of pyrimidine bases for nucleotide synthesis.

Thymidine phosphorylase; The enzymes which catalyze the reversible phosphorolysis of pyrimidine nucleosides are involved in the degradation of these compounds and in their utilization as carbon and energy sources, or in the rescue of pyrimidine bases for nucleotide synthesis; Belongs to the thymidine/pyrimidine-nucleoside phosphorylase family.

dUMP phosphatase; Nucleotidase that shows high phosphatase activity toward non- canonical pyrimidine nucleotides and three canonical nucleoside 5'- monophosphates (UMP, dUMP, and dTMP), and very low activity against TDP, IMP, UDP, GMP, dGMP, AMP, dAMP, and 6-phosphogluconate. Appears to function as a house-cleaning nucleotidase in vivo, since the general nucleotidase activity of YjjG allows it to protect cells against non- canonical pyrimidine derivatives such as 5-fluoro-2'-deoxyuridine, 5- fluorouridine, 5-fluoroorotate, 5-fluorouracil, and 5-aza-2'- deoxycytidine, and prevents the i [...]

Dihydroneopterin aldolase and dihydroneopterin triphosphate 2'-epimerase; Catalyzes the conversion of 7,8-dihydroneopterin to 6- hydroxymethyl-7,8-dihydropterin. Can use L-threo-dihydroneopterin and D-erythro-dihydroneopterin as substrates for the formation of 6- hydroxymethyldihydropterin, but it can also catalyze the epimerization of carbon 2' of dihydroneopterin to dihydromonapterin at appreciable velocity; Belongs to the DHNA family.

7,8-dihydropteroate synthase; Catalyzes the condensation of para-aminobenzoate (pABA) with 6-hydroxymethyl-7,8-dihydropterin diphosphate (DHPt-PP) to form 7,8- dihydropteroate (H2Pte), the immediate precursor of folate derivatives. Belongs to the DHPS family.

Dihydroneopterin aldolase and dihydroneopterin triphosphate 2'-epimerase; Catalyzes the conversion of 7,8-dihydroneopterin to 6- hydroxymethyl-7,8-dihydropterin. Can use L-threo-dihydroneopterin and D-erythro-dihydroneopterin as substrates for the formation of 6- hydroxymethyldihydropterin, but it can also catalyze the epimerization of carbon 2' of dihydroneopterin to dihydromonapterin at appreciable velocity; Belongs to the DHNA family.

4-hydroxy-L-threonine phosphate dehydrogenase, NAD-dependent; Catalyzes the NAD(P)-dependent oxidation of 4-(phosphooxy)-L- threonine (HTP) into 2-amino-3-oxo-4-(phosphooxy)butyric acid which spontaneously decarboxylates to form 3-amino-2-oxopropyl phosphate (AHAP); Belongs to the PdxA family.

Dihydroneopterin aldolase and dihydroneopterin triphosphate 2'-epimerase; Catalyzes the conversion of 7,8-dihydroneopterin to 6- hydroxymethyl-7,8-dihydropterin. Can use L-threo-dihydroneopterin and D-erythro-dihydroneopterin as substrates for the formation of 6- hydroxymethyldihydropterin, but it can also catalyze the epimerization of carbon 2' of dihydroneopterin to dihydromonapterin at appreciable velocity; Belongs to the DHNA family.

Pyridoxine 5'-phosphate synthase; Catalyzes the complicated ring closure reaction between the two acyclic compounds 1-deoxy-D-xylulose-5-phosphate (DXP) and 3-amino- 2-oxopropyl phosphate (1-amino-acetone-3-phosphate or AAP) to form pyridoxine 5'-phosphate (PNP) and inorganic phosphate.

Dihydroneopterin aldolase and dihydroneopterin triphosphate 2'-epimerase; Catalyzes the conversion of 7,8-dihydroneopterin to 6- hydroxymethyl-7,8-dihydropterin. Can use L-threo-dihydroneopterin and D-erythro-dihydroneopterin as substrates for the formation of 6- hydroxymethyldihydropterin, but it can also catalyze the epimerization of carbon 2' of dihydroneopterin to dihydromonapterin at appreciable velocity; Belongs to the DHNA family.

3-phosphoserine/phosphohydroxythreonine aminotransferase; Catalyzes the reversible conversion of 3- phosphohydroxypyruvate to phosphoserine and of 3-hydroxy-2-oxo-4- phosphonooxybutanoate to phosphohydroxythreonine. Is involved in both pyridoxine and serine biosynthesis; Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. SerC subfamily.

7,8-dihydropteroate synthase; Catalyzes the condensation of para-aminobenzoate (pABA) with 6-hydroxymethyl-7,8-dihydropterin diphosphate (DHPt-PP) to form 7,8- dihydropteroate (H2Pte), the immediate precursor of folate derivatives. Belongs to the DHPS family.

Dihydroneopterin aldolase and dihydroneopterin triphosphate 2'-epimerase; Catalyzes the conversion of 7,8-dihydroneopterin to 6- hydroxymethyl-7,8-dihydropterin. Can use L-threo-dihydroneopterin and D-erythro-dihydroneopterin as substrates for the formation of 6- hydroxymethyldihydropterin, but it can also catalyze the epimerization of carbon 2' of dihydroneopterin to dihydromonapterin at appreciable velocity; Belongs to the DHNA family.

7,8-dihydropteroate synthase; Catalyzes the condensation of para-aminobenzoate (pABA) with 6-hydroxymethyl-7,8-dihydropterin diphosphate (DHPt-PP) to form 7,8- dihydropteroate (H2Pte), the immediate precursor of folate derivatives. Belongs to the DHPS family.

Serine hydroxymethyltransferase; Catalyzes the reversible interconversion of serine and glycine with tetrahydrofolate (THF) serving as the one-carbon carrier. This reaction serves as the major source of one-carbon groups required for the biosynthesis of purines, thymidylate, methionine, and other important biomolecules. Also exhibits THF-independent aldolase activity toward beta-hydroxyamino acids, producing glycine and aldehydes, via a retro-aldol mechanism. Thus, is able to catalyze the cleavage of allothreonine and 3-phenylserine. Also catalyzes the irreversible conversion of 5,10-m [...]

7,8-dihydropteroate synthase; Catalyzes the condensation of para-aminobenzoate (pABA) with 6-hydroxymethyl-7,8-dihydropterin diphosphate (DHPt-PP) to form 7,8- dihydropteroate (H2Pte), the immediate precursor of folate derivatives. Belongs to the DHPS family.

Pyridoxine 5'-phosphate oxidase; Catalyzes the oxidation of either pyridoxine 5'-phosphate (PNP) or pyridoxamine 5'-phosphate (PMP) into pyridoxal 5'-phosphate (PLP).

7,8-dihydropteroate synthase; Catalyzes the condensation of para-aminobenzoate (pABA) with 6-hydroxymethyl-7,8-dihydropterin diphosphate (DHPt-PP) to form 7,8- dihydropteroate (H2Pte), the immediate precursor of folate derivatives. Belongs to the DHPS family.

Pyridoxine 5'-phosphate synthase; Catalyzes the complicated ring closure reaction between the two acyclic compounds 1-deoxy-D-xylulose-5-phosphate (DXP) and 3-amino- 2-oxopropyl phosphate (1-amino-acetone-3-phosphate or AAP) to form pyridoxine 5'-phosphate (PNP) and inorganic phosphate.

7,8-dihydropteroate synthase; Catalyzes the condensation of para-aminobenzoate (pABA) with 6-hydroxymethyl-7,8-dihydropterin diphosphate (DHPt-PP) to form 7,8- dihydropteroate (H2Pte), the immediate precursor of folate derivatives. Belongs to the DHPS family.

Thymidylate synthetase; Catalyzes the reductive methylation of 2'-deoxyuridine-5'- monophosphate (dUMP) to 2'-deoxythymidine-5'-monophosphate (dTMP) while utilizing 5,10-methylenetetrahydrofolate (mTHF) as the methyl donor and reductant in the reaction, yielding dihydrofolate (DHF) as a by-product. This enzymatic reaction provides an intracellular de novo source of dTMP, an essential precursor for DNA biosynthesis. This protein also binds to its mRNA thus repressing its own translation.

Glycine cleavage complex lipoylprotein; The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein.

Glycine decarboxylase, PLP-dependent, subunit P of glycine cleavage complex; The glycine cleavage system catalyzes the degradation of glycine. The P protein binds the alpha-amino group of glycine through its pyridoxal phosphate cofactor; CO(2) is released and the remaining methylamine moiety is then transferred to the lipoamide cofactor of the H protein; Belongs to the GcvP family.

Glycine cleavage complex lipoylprotein; The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein.

Aminomethyltransferase, tetrahydrofolate-dependent, subunit (T protein) of glycine cleavage complex; The glycine cleavage system catalyzes the degradation of glycine.

Glycine cleavage complex lipoylprotein; The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein.

Serine hydroxymethyltransferase; Catalyzes the reversible interconversion of serine and glycine with tetrahydrofolate (THF) serving as the one-carbon carrier. This reaction serves as the major source of one-carbon groups required for the biosynthesis of purines, thymidylate, methionine, and other important biomolecules. Also exhibits THF-independent aldolase activity toward beta-hydroxyamino acids, producing glycine and aldehydes, via a retro-aldol mechanism. Thus, is able to catalyze the cleavage of allothreonine and 3-phenylserine. Also catalyzes the irreversible conversion of 5,10-m [...]

Glycine cleavage complex lipoylprotein; The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein.

Dihydrolipoyl dehydrogenase; Lipoamide dehydrogenase is a component of the glycine cleavage system as well as of the alpha-ketoacid dehydrogenase complexes.

Glycine cleavage complex lipoylprotein; The glycine cleavage system catalyzes the degradation of glycine. The H protein shuttles the methylamine group of glycine from the P protein to the T protein.

3-phosphoserine/phosphohydroxythreonine aminotransferase; Catalyzes the reversible conversion of 3- phosphohydroxypyruvate to phosphoserine and of 3-hydroxy-2-oxo-4- phosphonooxybutanoate to phosphohydroxythreonine. Is involved in both pyridoxine and serine biosynthesis; Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. SerC subfamily.