Download MendeleyThe Mycobacterium tuberculosis mycothiol S -transferase is divalent metal-dependent for mycothiol binding and transfer.
Jayasinghe, Y.P., Banco, M.T., Lindenberger, J.J., Favrot, L., Palcekova, Z., Jackson, M., Manabe, S., Ronning, D.R.(2023) RSC Med Chem 14: 491-500
- PubMed: 36970142
- DOI: https://doi.org/10.1039/d2md00401a
- Primary Citation of Related Structures:
8F5V, 8FX9 - PubMed Abstract:
Mycothiol S -transferase (MST) (encoded by the rv0443 gene) was previously identified as the enzyme responsible for the transfer of Mycothiol (MSH) to xenobiotic acceptors in Mycobacterium tuberculosis ( M.tb ) during xenobiotic stress. To further characterize the functionality of MST in vitro and the possible roles in vivo , X-ray crystallographic, metal-dependent enzyme kinetics, thermal denaturation studies, and antibiotic MIC determination in rv0433 knockout strain were performed. The binding of MSH and Zn 2+ increases the melting temperature by 12.9 °C as a consequence of the cooperative stabilization of MST by both MSH and metal. The co-crystal structure of MST in complex with MSH and Zn 2+ to 1.45 Å resolution supports the specific utilization of MSH as a substrate as well as affording insights into the structural requirements of MSH binding and the metal-assisted catalytic mechanism of MST. Contrary to the well-defined role of MSH in mycobacterial xenobiotic responses and the ability of MST to bind MSH, cell-based studies with an M.tb rv0443 knockout strain failed to provide evidence for a role of MST in processing of rifampicin or isoniazid. These studies suggest the necessity of a new direction to identify acceptors of the enzyme and better define the biological role of MST in mycobacteria.
Organizational Affiliation:
Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center Omaha Nebraska USA don.ronning@unmc.edu.
