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Updated: Nov 23, 2025
X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Structural analysis of Mycobacterium tuberculosis M13 metalloprotease Zmp1 open states
Wenguang G Liang1, Jordan M Mancl1, Minglei Zhao2
1Ben May Department for Cancer Research, The University of Chicago, Chicago, IL 60637, USA.
Abstract:
Zinc metalloprotease 1 (Zmp1), a Mycobacterium tuberculosis 75 kDa secreted enzyme, mediates key stages of tuberculosis disease progression. The biological activity of Zmp1 presumably stems from its ability to degrade bacterium- and/or host-derived peptides. The crystal structures of Zmp1 and related M13 metalloproteases, such as neprilysin and endothelin-converting enzyme-1 were determined only in the closed conformation, which cannot capture substrates or release proteolytic products. Thus, the mechanisms of substrate binding and selectivity remain elusive. Here we report two open-state cryo-EM structures of Zmp1, revealed by our SAXS analysis to be the dominant states in solution. Our structural analyses reveal how ligand binding induces a conformational switch in four linker regions to drive the rigid body motion of the D1 and D2 domains, which form the sizable catalytic chamber. Furthermore, they offer insights into the catalytic cycle and mechanism of substrate recognition of M13 metalloproteases for future therapeutic innovations.
Insights
This study reveals the open-state structures of Mycobacterium tuberculosis Zinc metalloprotease 1 (Zmp1), a key enzyme in tuberculosis. These structures explain how Zmp1 binds substrates, offering new avenues for therapeutic interventions against tuberculosis.
Area of Science:
- Structural biology
- Biochemistry
- Microbiology
Background:
- Mycobacterium tuberculosis Zinc metalloprotease 1 (Zmp1) is a secreted enzyme crucial for tuberculosis pathogenesis.
- Zmp1's function involves degrading host- and bacterium-derived peptides.
- Previous crystal structures of Zmp1 and related M13 metalloproteases were only in closed conformations, hindering understanding of substrate interactions.
Purpose of the Study:
- To determine the open-state structures of Zmp1.
- To elucidate the mechanisms of substrate binding and selectivity in M13 metalloproteases.
- To provide insights for developing novel therapeutics against tuberculosis.
Main Methods:
- Cryo-electron microscopy (cryo-EM) to obtain high-resolution structures.
- Small-angle X-ray scattering (SAXS) to determine dominant solution states.
- Structural analysis of conformational changes upon ligand binding.
Main Results:
- Two open-state cryo-EM structures of Zmp1 were determined, representing dominant solution conformations.
- Ligand binding was shown to induce conformational switches in four linker regions.
- These switches drive rigid body motion of the D1 and D2 domains, opening the catalytic chamber.
Conclusions:
- The open-state structures provide mechanistic insights into substrate binding and recognition for M13 metalloproteases.
- Understanding Zmp1's conformational dynamics is key to its catalytic cycle.
- These findings pave the way for future therapeutic strategies targeting Zmp1 in tuberculosis treatment.
