Tryptophan synthase, alpha subunit; The alpha subunit is responsible for the aldol cleavage of indoleglycerol phosphate to indole and glyceraldehyde 3-phosphate. Belongs to the TrpA family.

The N-(5'-phosphoribosyl)anthranilate isomerase (PRAI) converts the N-(5-phospho-beta-D-ribosyl)anthranilate to 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate, the third step in the biosynthesis of tryptophan; Localized in the cytoplasm; High confidence in function and specificity; Belongs to the TrpF family.

Anthranilate phosphoribosyltransferase; Catalyzes the transfer of the phosphoribosyl group of 5- phosphorylribose-1-pyrophosphate (PRPP) to anthranilate to yield N-(5'- phosphoribosyl)-anthranilate (PRA).

Anthranilate synthase component II (glutamine amidotransferase); The anthranilate synthase catalyzes the formation of anthranilate from chorismate and L-glutamine, the first step in the biosynthesis of tryptophan. The enzyme is a Tetramer of two components I and two components II. Associated with the component I, the component II of the anthranilate synthase provides the glutamine amidotransferase activity (GATase, 2.4.2.-) that catalyses the removal of the ammonia group from a glutamate molecule and its subsequent transfer to a specific substrate, thus creating a new carbon-nitrogen g [...]

The anthranilate synthase catalyzes the formation of anthranilate from chorismate and L-glutamine, the first step in the biosynthesis of tryptophan. The enzyme is a Tetramer of two components I and two components II. The component I only catalyzes the formation of anthranilate using chorismate and ammonia rather than glutamine; The anthranilate synthase is regulated by feedback inhibition by tryptophan; Belongs to the anthranilate synthase component I family; Localized in the cytoplasm; High confidence in function and specificity.

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.

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.

Tryptophan synthase beta subunit; The beta subunit is responsible for the synthesis of L- tryptophan from indole and L-serine.

The cysteine synthase is the enzyme responsible for the formation of cysteine from O-acetyl-serine and hydrogen sulfide with the concomitant release of acetic acid; Uses the pyridoxal phosphate as cofactor (vitamin B6) attached to a conserved lysine residue; Belongs to the cysteine synthase/cystathionine beta-synthase family; Localized in the cytoplasm; High confidence in function and specificity.