A structural model for chorismate synthase from Mycobacterium tuberculosis in complex with coenzyme and substrate

Area of Science:

• Biochemistry
• Structural Biology
• Drug Discovery

Background:

• The shikimate pathway is crucial for bacterial survival and a promising target for novel antibacterial agents.
• Chorismate synthase (CS) is the final enzyme in this pathway, making it a key target for therapeutic intervention.

Purpose of the Study:

• To predict the three-dimensional structure of Mycobacterium tuberculosis chorismate synthase (MTB CS).
• To computationally dock the coenzyme flavin mononucleotide (FMN) and the substrate 5-enolpyruvylshikimate-3-phosphate (EPSP) into the predicted MTB CS structure.

Main Methods:

• Homology modeling was used to predict the MTB CS structure based on the crystal structure of Streptococcus pneumoniae CS.
• Geometric docking simulations were performed to analyze the binding of FMN and EPSP to the MTB CS model.
• Energy minimization was applied to the docked complex to refine interactions.

Main Results:

• The predicted MTB CS structure largely preserved interactions from the template, with notable exceptions at HIS11, ARG139, and GLN255.
• Novel interactions were identified involving ARG111, GLY113, and SER317 within the MTB CS active site.
• These findings provide insights into the specific binding characteristics of MTB CS.

Conclusions:

• The predicted structure and docking analysis offer a valuable resource for understanding MTB CS.
• Identified interactions can guide the rational design of specific inhibitors targeting MTB CS.
• This research contributes to the development of new antibacterial strategies against Mycobacterium tuberculosis.