Methionine synthase; Catalyzes the transfer of a methyl group from methyl- cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate.

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.

Glycine cleavage system protein H; Is also involved in protein lipoylation via its role as an octanoyl/lipoyl carrier protein intermediate; Belongs to the GcvH family.

Dual specificity protein phosphatase.

Bifunctional protein FolD protein; Catalyzes the oxidation of 5,10-methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate and then the hydrolysis of 5,10- methenyltetrahydrofolate to 10-formyltetrahydrofolate.

Methenyltetrahydrofolate cyclohydrolase; Catalyzes the oxidation of 5,10-methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate and then the hydrolysis of 5,10- methenyltetrahydrofolate to 10-formyltetrahydrofolate.

Phosphopantothenoylcysteine decarboxylase/phosphopantothenate--cysteine ligase; Catalyzes two steps in the biosynthesis of coenzyme A. In the first step cysteine is conjugated to 4'-phosphopantothenate to form 4- phosphopantothenoylcysteine, in the latter compound is decarboxylated to form 4'-phosphopantotheine; In the C-terminal section; belongs to the PPC synthetase family.