Glycine cleavage complex protein T, aminomethyltransferase, tetrahydrofolate-dependent; The glycine cleavage system catalyzes the degradation of glycine.

Putative orphan protein; No homology to any previously reported sequences.

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.

Bifunctional: 5,10-methylene-tetrahydrofolate dehydrogenase; Catalyzes the oxidation of 5,10-methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate and then the hydrolysis of 5,10- methenyltetrahydrofolate to 10-formyltetrahydrofolate.

Dihydrolipoyl dehydrogenase; Function of homologous gene experimentally demonstrated in an other organism; enzyme.

Putative pyridine nucleotide-disulfide oxidoreductase, class I; Function proposed based on presence of conserved amino acid motif, structural feature or limited homolgy.

Lipoyl synthase; Catalyzes the radical-mediated insertion of two sulfur atoms into the C-6 and C-8 positions of the octanoyl moiety bound to the lipoyl domains of lipoate-dependent enzymes, thereby converting the octanoylated domains into lipoylated derivatives.

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.