Structure of Chorismate Mutase-like Domain of DAHPS from Bacillus subtilis Complexed with Novel Inhibitor Reveals Conformational Plasticity of Active Site

Sci Rep. 2017 Jul 25;7(1):6364. doi: 10.1038/s41598-017-06578-1.

Abstract

3-deoxy-D-arabino-heptulosonate-7-phosphate-synthase (DAHPS) is the first enzyme of the shikimate pathway and is responsible for the synthesis of aromatic amino acids in microorganisms. This pathway is an attractive target for antimicrobial drugs. In Bacillus subtilis, the N-terminal domain of the bifunctional DAHPS enzyme belongs to an AroQ class of chorismate mutase and is functionally homologous to the downstream AroH class chorismate mutase. This is the first structure of chorismate mutase, AroQ (BsCM_2) enzyme from Bacillus subtilis in complex with citrate and chlorogenic acid at 1.9 Å and 1.8 Å resolution, respectively. This work provides the structural basis of ligand binding into the active site of AroQ class of chorismate mutase, while accompanied by the conformational flexibility of active site loop. Molecular dynamics results showed that helix H2' undergoes uncoiling at the first turn and increases the mobility of loop L1'. The side chains of Arg45, Phe46, Arg52 and Lys76 undergo conformational changes, which may play an important role in DAHPS regulation by the formation of the domain-domain interface. Additionally, binding studies showed that the chlorogenic acid binds to BsCM_2 with a higher affinity than chorismate. These biochemical and structural findings could lead to the development of novel antimicrobial drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Deoxy-7-Phosphoheptulonate Synthase / chemistry*
  • 3-Deoxy-7-Phosphoheptulonate Synthase / metabolism*
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Bacillus subtilis / chemistry
  • Bacillus subtilis / drug effects
  • Bacillus subtilis / enzymology*
  • Bacterial Proteins / chemistry
  • Binding Sites
  • Catalytic Domain
  • Chlorogenic Acid / chemistry
  • Chlorogenic Acid / pharmacology*
  • Chorismate Mutase / chemistry
  • Chorismate Mutase / metabolism
  • Citric Acid / chemistry
  • Citric Acid / pharmacology
  • Crystallography, X-Ray
  • Kinetics
  • Microbial Sensitivity Tests
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Protein Structure, Secondary

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Citric Acid
  • Chlorogenic Acid
  • 3-Deoxy-7-Phosphoheptulonate Synthase
  • Chorismate Mutase