Cryo-EM structure of the Mycobacterium abscessus F₁-ATPase

Area of Science:

• Biochemistry
• Structural Biology
• Microbiology

Background:

• Increasing lung disease cases caused by Mycobacterium abscessus (Mab) necessitate novel therapeutic targets.
• The oxidative phosphorylation pathway and its ATP synthase are attractive targets for Mab inhibitors.

Purpose of the Study:

• To generate and purify a recombinant, active Mycobacterium abscessus F1-ATPase complex (MabF1-αβγδε).
• To gain mechanistic, regulatory, and structural insights into the Mab F1-ATPase.
• To determine the first cryo-electron microscopy structure of the Mab F1-ATPase complex.

Main Methods:

• Expression and purification of the recombinant MabF1-αβγδε complex.
• Cryo-electron microscopy for structural determination.
• Enzymatic assays to measure ATP hydrolysis activity.

Main Results:

• A highly pure and enzymatically active MabF1-αβγδε complex was obtained.
• The first cryo-electron microscopy structure of the Mab F1-ATPase was determined at 7.3 Å resolution.
• The enzyme exhibited low basal ATP hydrolysis activity, which was enhanced by trypsin treatment.

Conclusions:

• The characterized Mab F1-ATPase complex provides a foundation for understanding its function and developing inhibitors.
• Structural insights into the Mab F1-ATPase can guide the design of novel anti-mycobacterial drugs.
• Targeting the F1-ATPase represents a promising strategy for treating non-tuberculous mycobacterial lung infections.