cysteine--tRNA ligase; Derived by automated computational analysis using gene prediction method: Protein Homology; Belongs to the class-I aminoacyl-tRNA synthetase family.

Serine acetyltransferase; Derived by automated computational analysis using gene prediction method: Protein Homology.

L-serine ammonia-lyase; Derived by automated computational analysis using gene prediction method: Protein Homology; Belongs to the iron-sulfur dependent L-serine dehydratase family.

2,3-diaminopropionate biosynthesis protein SbnA; Derived by automated computational analysis using gene prediction method: Protein Homology.

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

Phosphoserine phosphatase SerB; Derived by automated computational analysis using gene prediction method: Protein Homology.

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.

PLP-dependent 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.