Cystathionine beta-lyase; Catalyzes the formation of L-homocysteine from cystathionine; Derived by automated computational analysis using gene prediction method: Protein Homology.

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.

5-methyltetrahydrofolate--homocysteine methyltransferase; Derived by automated computational analysis using gene prediction method: Protein Homology.

O-succinylhomoserine sulfhydrylase; Catalyzes the formation of L-homocysteine from O-succinyl-L- homoserine (OSHS) and hydrogen sulfide.

Adenosylhomocysteinase; May play a key role in the regulation of the intracellular concentration of adenosylhomocysteine.

Homoserine dehydrogenase; Catalyzes the formation of L-aspartate 4-semialdehyde from L-homoserine; Derived by automated computational analysis using gene prediction method: Protein Homology.

Pyridoxal-5'-phosphate-dependent protein subunit beta; Derived by automated computational analysis using gene prediction method: Protein Homology.

Threonine dehydratase; Catalyzes the anaerobic formation of alpha-ketobutyrate and ammonia from threonine in a two-step reaction. The first step involved a dehydration of threonine and a production of enamine intermediates (aminocrotonate), which tautomerizes to its imine form (iminobutyrate). Both intermediates are unstable and short-lived. The second step is the nonenzymatic hydrolysis of the enamine/imine intermediates to form 2- ketobutyrate and free ammonia. In the low water environment of the cell, the second step is accelerated by RidA.

Homoserine kinase; Catalyzes the formation of O-phospho-L-homoserine from L-homoserine; Derived by automated computational analysis using gene prediction method: Protein Homology; Belongs to the pseudomonas-type ThrB family.