title: Characterization of MymA protein as a flavin-containing monooxygenase and as a target of isoniazid.
abstract: Tuberculosis is a global health problem especially with the emergence of drug-resistant Mycobacterium tuberculosis strains, creating an urgent need to identify new drug targets. The mycobacterial cell wall is an attractive target for chemotherapeutic agents. Gene products of mymA operon are known to be required for the maintenance of cell wall and play an important role in persistence, thus making them important drug targets. This study was undertaken to biochemically characterize the MymA as a flavin-containing monooxygenase (FMO). Our results established its enzymatic activity in vitro and found that the mycobacterial FMO requires NADPH and FAD as cofactors, similar to other characterized bacterial FMOs. The enzyme follows Michaelis-Menten kinetics to catalyze substrates such as trimethylamine and thiourea. We also propose that MymA could be one of the targets of the antituberculosis drug, isoniazid (INH), which is a cell wall inhibitor. Molecular docking studies revealed that INH targeted NADPH-binding site of the MymA. Further, experimental validation revealed that INH inhibits MymA with the IC50value of 4.9 μm. Thus, this study characterizes for the first time that MymA is a mycobacterial FMO, which may be a target of INH.
authors.affiliation: D S Kothari Centre for Research and Innovation in Science Education, Miranda House, Delhi, India.|Department of Zoology, Miranda House, University of Delhi, Delhi, India.
authors.forename: Iti
authors.initials: I
authors.lastname: Saraav
authors.affiliation: D S Kothari Centre for Research and Innovation in Science Education, Miranda House, Delhi, India.|Department of Zoology, Miranda House, University of Delhi, Delhi, India.
authors.forename: Kirti
authors.identifier: http://orcid.org/0000-0003-0799-6376
authors.initials: K
authors.lastname: Pandey
authors.affiliation: D S Kothari Centre for Research and Innovation in Science Education, Miranda House, Delhi, India.|Department of Zoology, Miranda House, University of Delhi, Delhi, India.
authors.forename: Richa
authors.initials: R
authors.lastname: Misra
authors.affiliation: D S Kothari Centre for Research and Innovation in Science Education, Miranda House, Delhi, India.|Department of Zoology, Miranda House, University of Delhi, Delhi, India.
authors.forename: Swati
authors.initials: S
authors.lastname: Singh
authors.affiliation: D S Kothari Centre for Research and Innovation in Science Education, Miranda House, Delhi, India.|Department of Zoology, Miranda House, University of Delhi, Delhi, India.
authors.forename: Monika
authors.initials: M
authors.lastname: Sharma
authors.affiliation: D S Kothari Centre for Research and Innovation in Science Education, Miranda House, Delhi, India.|Department of Zoology, Miranda House, University of Delhi, Delhi, India.
authors.forename: Sadhna
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000595:Amino Acid Sequence; D000995:Antitubercular Agents / Q000737:chemistry / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000187:drug effects*; D005415:Flavins / Q000032:analysis*; D007538:Isoniazid / Q000737:chemistry / Q000494:pharmacology*; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000187:drug effects*; D062105:Molecular Docking Simulation; D017386:Sequence Homology, Amino Acid
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D005415:Flavins; D006899:Mixed Function Oxygenases; D007538:Isoniazid
keywords: FMO; INH; Molecular docking; Mycobacterium tuberculosis; MymA