Chorismate mutase (AroH)

 

Chorismate mutase (CM; EC:5.4.99.5) catalyses the rearrangement of chorismate to prephenat, the reaction at the branch point of the biosynthetic pathway leading to the three aromatic amino acids, phenylalanine, tryptophan and tyrosine (chorismic acid is the last common intermediate, and CM leads to the L-phenylalanine/L-tyrosine branch). It is part of the shikimate pathway, which is present only in bacteria, fungi and plants.

This entry represents a family of monofunctional (non-fused) chorismate mutases from Gram-positive bacteria (Firmicutes) and cyanobacteria. They are monofunctional, homotrimeric, non-allosteric enzymes and are not regulated by the end-product aromatic amino acids (unlike those CMs of the AroQ-type).

 

Reference Protein and Structure

Sequence
P19080 UniProt (5.4.99.5) IPR008243 (Sequence Homologues) (PDB Homologues)
Biological species
Bacillus subtilis subsp. subtilis str. 168 (Bacteria) Uniprot
PDB
3zo8 - Wild-type chorismate mutase of Bacillus subtilis at 1.6 A resolution (1.59 Å) PDBe PDBsum 3zo8
Catalytic CATH Domains
3.30.1330.40 CATHdb (see all for 3zo8)
Click To Show Structure

Enzyme Reaction (EC:5.4.99.5)

chorismate(2-)
CHEBI:29748ChEBI
→
(1s,4s)-prephenate(2-)
CHEBI:29934ChEBI
Alternative enzyme names: Hydroxyphenylpyruvate synthase,

Enzyme Mechanism

Introduction

Chorismate mutase uses an extensive array of hydrogen-bonding and electrostatic interactions to bind the pseudodiaxial substrate conformer. Sterically constraining chorismate in a “near attack conformation” (NAC), in which the reacting centres are confined to contact distances. Further, ground state destabilisation through conformational compression has been shown to afford large rate accelerations for Claisen rearrangements in synthetic model systems. Polar active site residues, most notably a cationic arginine or lysine positioned next to the ether oxygen of the breaking C–O bond, stabilise the high-energy transition state electrostatically relative to the bound substrate.

The rearrangement of chorismate to prephenate occurs in a single step via a chair-like transition state. Cleavage of the C-O bond goes slightly ahead of the new C-C bond formation, so there is a partial negative charge on the ether oxygen of chorismate in the transition state.

Catalytic Residues Roles

UniProt PDB* (3zo8)
Arg7, Glu78, Arg116, Tyr108, Arg90, Arg63, Cys75 Arg7D, Glu78D, Arg116D, Tyr108D, Arg90D, Arg63F, Cys75F Forms part of the electrostatic environment that stabilises the transition state over either the substrate or product states. transition state stabiliser
*PDB label guide - RESx(y)B(C) - RES: Residue Name; x: Residue ID in PDB file; y: Residue ID in PDB sequence if different from PDB file; B: PDB Chain; C: Biological Assembly Chain if different from PDB. If label is "Not Found" it means this residue is not found in the reference PDB.

Chemical Components

pericyclic reaction, claisen rearrangement

References

  1. Burschowsky D et al. (2014), Proc Natl Acad Sci U S A, 111, 17516-17521. Electrostatic transition state stabilization rather than reactant destabilization provides the chemical basis for efficient chorismate mutase catalysis. DOI:10.1073/pnas.1408512111. PMID:25422475.
  2. Claeyssens F et al. (2011), Org Biomol Chem, 9, 1578-1590. Analysis of chorismate mutase catalysis by QM/MM modelling of enzyme-catalysed and uncatalysed reactions. DOI:10.1039/c0ob00691b. PMID:21243152.
  3. Ishida T (2010), J Am Chem Soc, 132, 7104-7118. Effects of Point Mutation on Enzymatic Activity: Correlation between Protein Electronic Structure and Motion in Chorismate Mutase Reaction. DOI:10.1021/ja100744h. PMID:20426479.
  4. Szefczyk B et al. (2007), Int J Quantum Chem, 107, 2274-2285. Quantum chemical analysis of reaction paths in chorismate mutase: Conformational effects and electrostatic stabilization. DOI:10.1002/qua.21354.
  5. Helmstaedt K et al. (2004), Arch Microbiol, 181, 195-203. Chorismate mutase of Thermus thermophilus is a monofunctional AroH class enzyme inhibited by tyrosine. DOI:10.1007/s00203-003-0639-z. PMID:14727008.
  6. Szefczyk B et al. (2004), J Am Chem Soc, 126, 16148-16159. Differential Transition-State Stabilization in Enzyme Catalysis:  Quantum Chemical Analysis of Interactions in the Chorismate Mutase Reaction and Prediction of the Optimal Catalytic Field. DOI:10.1021/ja049376t. PMID:15584751.
  7. Martí S et al. (2003), Org Biomol Chem, 1, 483-487. QM/MM calculations of kinetic isotope effects in the chorismate mutase active site. DOI:10.1039/b210508j.
  8. Hur S et al. (2003), Proc Natl Acad Sci U S A, 100, 12015-12020. The near attack conformation approach to the study of the chorismate to prephenate reaction. DOI:10.1073/pnas.1534873100. PMID:14523243.
  9. Strajbl M et al. (2003), J Am Chem Soc, 125, 10228-10237. Apparent NAC Effect in Chorismate Mutase Reflects Electrostatic Transition State Stabilization. DOI:10.1021/ja0356481. PMID:12926945.
  10. Kienhöfer A et al. (2003), J Am Chem Soc, 125, 3206-3207. Selective Stabilization of the Chorismate Mutase Transition State by a Positively Charged Hydrogen Bond Donor. DOI:10.1021/ja0341992. PMID:12630863.
  11. Guimarães CR et al. (2003), J Am Chem Soc, 125, 6892-6899. Contributions of Conformational Compression and Preferential Transition State Stabilization to the Rate Enhancement by Chorismate Mutase. DOI:10.1021/ja021424r. PMID:12783541.
  12. Hur S et al. (2003), J Am Chem Soc, 125, 10540-10542. Just a Near Attack Conformer for Catalysis (Chorismate to Prephenate Rearrangements in Water, Antibody, Enzymes, and Their Mutants). DOI:10.1021/ja0357846. PMID:12940735.
  13. Martí S et al. (2003), Chemistry, 9, 984-991. Preorganization and Reorganization as Related Factors in Enzyme Catalysis: The Chorismate Mutase Case. DOI:10.1002/chem.200390121. PMID:12584715.
  14. Guo H et al. (2003), Angew Chem Int Ed Engl, 42, 1508-1511. Understanding the Role of Active-Site Residues in Chorismate Mutase Catalysis from Molecular-Dynamics Simulations. DOI:10.1002/anie.200219878. PMID:12698486.
  15. Martí S et al. (2001), J Am Chem Soc, 123, 1709-1712. A Hybrid Potential Reaction Path and Free Energy Study of the Chorismate Mutase Reaction. DOI:10.1021/ja003522n.
  16. Worthington SE et al. (2001), J Phys Chem B, 105, 7087-7095. An MD/QM Study of the Chorismate Mutase-Catalyzed Claisen Rearrangement Reaction. DOI:10.1021/jp010227w.
  17. Kast P et al. (2000), J Biol Chem, 275, 36832-36838. A Strategically Positioned Cation Is Crucial for Efficient Catalysis by Chorismate Mutase. DOI:10.1074/jbc.m006351200. PMID:10960481.
  18. Gamper M et al. (2000), Biochemistry, 39, 14087-14094. Probing the Role of the C-Terminus ofBacillus subtilisChorismate Mutase by a Novel Random Protein-Termination Strategy†. DOI:10.1021/bi0016570.
  19. Khanjin NA et al. (1999), J Am Chem Soc, 121, 11831-11846. Mechanism of Chorismate Mutase:  Contribution of Conformational Restriction to Catalysis in the Claisen Rearrangement. DOI:10.1021/ja992453d.
  20. Mattei P et al. (1999), Eur J Biochem, 261, 25-32. Bacillus subtilis chorismate mutase is partially diffusion-controlled. DOI:10.1046/j.1432-1327.1999.00169.x.
  21. Kast P et al. (1996), J Am Chem Soc, 118, 3069-3070. Electrostatic Catalysis of the Claisen Rearrangement:  Probing the Role of Glu78 inBacillus subtilisChorismate Mutase by Genetic Selection. DOI:10.1021/ja953701i.
  22. Cload ST et al. (1996), J Am Chem Soc, 118, 1787-1788. Mutagenesis Study of Active Site Residues in Chorismate Mutase fromBacillus subtilis. DOI:10.1021/ja953152g.
  23. Kast P et al. (1996), Proc Natl Acad Sci U S A, 93, 5043-5048. Exploring the active site of chorismate mutase by combinatorial mutagenesis and selection: the importance of electrostatic catalysis. PMID:8643526.
  24. Lyne PD et al. (1995), J Am Chem Soc, 117, 11345-11350. Insights into Chorismate Mutase Catalysis from a Combined QM/MM Simulation of the Enzyme Reaction. DOI:10.1021/ja00150a037.
  25. Lee A et al. (1995), Chem Biol, 2, 195-203. New insight into the catalytic mechanism of chorismate mutases from structural studies. DOI:10.1016/1074-5521(95)90269-4.
  26. Chook YM et al. (1994), J Mol Biol, 240, 476-500. The Monofunctional Chorismate Mutase from Bacillus subtilis. DOI:10.1006/jmbi.1994.1462. PMID:8046752.
  27. Chook YM et al. (1993), Proc Natl Acad Sci U S A, 90, 8600-8603. Crystal structures of the monofunctional chorismate mutase from Bacillus subtilis and its complex with a transition state analog. PMID:8378335.

Step 1. The substrate undergoes the pericyclic Claisen rearrangement.

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Catalytic Residues Roles

Residue Roles
Arg7D transition state stabiliser
Glu78D transition state stabiliser
Arg90D transition state stabiliser
Tyr108D transition state stabiliser
Arg116D transition state stabiliser
Arg63F transition state stabiliser
Cys75F transition state stabiliser

Chemical Components

pericyclic reaction, claisen rearrangement
Download: Image, Marvin File

Step 1. The substrate undergoes the pericyclic Claisen rearrangement.

Products.

Contributors

Gemma L. Holliday, Steven Smith