8EH0

Engineered tyrosine synthase (TmTyrS1) derived from T. maritima TrpB with Ser bound as the amino-acrylate intermediate and complexed with quinoline N-oxide

Summary for 8EH0

• Entry DOI: 10.2210/pdb8eh0/pdb
• Descriptor: Tryptophan synthase beta chain 1, 2-{[(E)-{3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}methylidene]amino}prop-2-enoic acid, 1,2-ETHANEDIOL, ... (6 entities in total)
• Functional Keywords: tyrosine synthase, engineered enzyme, noncanonical amino acid synthase, biosynthetic protein
• Biological source: Thermotoga maritima
• Total number of polymer chains: 2
• Total formula weight: 88652.75

Authors

Porter, N.J.,Almhjell, P.J.,Arnold, F.H. (deposition date: 2022-09-13, release date: 2023-10-04, Last modification date: 2024-08-14)

Primary citation

Almhjell, P.J.,Johnston, K.E.,Porter, N.J.,Kennemur, J.L.,Bhethanabotla, V.C.,Ducharme, J.,Arnold, F.H.
The beta-subunit of tryptophan synthase is a latent tyrosine synthase.
Nat.Chem.Biol., 20:1086-1093, 2024

PubMed Abstract: Aromatic amino acids and their derivatives are diverse primary and secondary metabolites with critical roles in protein synthesis, cell structure and integrity, defense and signaling. All de novo aromatic amino acid production relies on a set of ancient and highly conserved chemistries. Here we introduce a new enzymatic transformation for L-tyrosine synthesis by demonstrating that the β-subunit of tryptophan synthase-which natively couples indole and L-serine to form L-tryptophan-can act as a latent 'tyrosine synthase'. A single substitution of a near-universally conserved catalytic residue unlocks activity toward simple phenol analogs and yields exclusive para carbon-carbon bond formation to furnish L-tyrosines. Structural and mechanistic studies show how a new active-site water molecule orients phenols for a nonnative mechanism of alkylation, with additional directed evolution resulting in a net >30,000-fold rate enhancement. This new biocatalyst can be used to efficiently prepare valuable L-tyrosine analogs at gram scales and provides the missing chemistry for a conceptually different pathway to L-tyrosine.

PubMed: 38744987
DOI: 10.1038/s41589-024-01619-z

Experimental method

X-RAY DIFFRACTION (1.7 Å)