Abstract
A novel mechanism of rifampicin (Rif) resistance has recently been reported in Nocardia farcinica. This new mechanism involves the activity of rifampicin monooxygenase (RifMO), a flavin-dependent monooxygenase that catalyzes the hydroxylation of Rif, which is the first step in the degradation pathway. Recombinant RifMO was overexpressed and purified for biochemical analysis. Kinetic characterization revealed that Rif binding is necessary for effective FAD reduction. RifMO exhibits only a 3-fold coenzyme preference for NADPH over NADH. RifMO catalyzes the incorporation of a single oxygen atom forming an unstable intermediate that eventually is converted to 20-N-hydroxy-4-oxo-Rif. Stable C4a-hydroperoxyflavin was not detected by rapid kinetics methods, which is consistent with only 30% of the activated oxygen leading to product formation. These findings represent the first reported detailed biochemical characterization of a flavin-monooxygenase involved in antibiotic resistance.
Recommended Citation
H. Abdelwahab et al., "Mechanism of Rifampicin Inactivation in Nocardia Farcinica," PLoS ONE, vol. 11, no. 10, article no. e0162578, Public Library of Science, Oct 2016.
The definitive version is available at https://doi.org/10.1371/journal.pone.0162578
Department(s)
Chemistry
Publication Status
Open Access
International Standard Serial Number (ISSN)
1932-6203
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Oct 2016
PubMed ID
27706151
Comments
National Science Foundation, Grant 1021384