Nitroreductases catalyse the NAD(P)H-dependent nitro reduction in nitrofuran antibiotics, which activates them into cytotoxic molecules leading to cell death. The design of new effective nitrofuran antibiotics relies on knowledge of the kinetic mechanism and nitrofuran binding mode of microbial nitroreductases NfsA and NfsB. This has been hampered by multiple co-crystallisation studies revealing ligand binding in non-electron transfer competent states. In a recent study by Day et al. (2021) the authors investigated the likely reaction mechanism and mode of nitrofurantoin binding to NfsA using potentiometry, global kinetics analysis, crystallography and molecular dynamics simulations. Their findings suggest nitrofurantoin reduction proceeds via a direct hydride transfer from reduced FMN, while the crystallographic binding orientation is an inhibitory complex. Molecular dynamics simulations suggest ligand binding orientations is dependent on the oxidation state of the FMN. This study highlights the importance of utilising computational studies alongside traditional crystallographic approaches, when multiple stable ligand binding orientations can occur.
-
Cover Image
Cover Image
In this issue, Witus and colleagues (pp. 3467–3483) discuss the Ub ligase function of BRCA1/BARD1, highlighting experimental approaches, mechanistic considerations, and reagents that are useful in the study of substrate ubiquitylation. The review also looks at the current understanding of two well established BRCA1/BARD1 substrates and several recently discovered substrates. The cover image shows that BRCA1 and BARD1 bind the nucleosome substrate and E2 simultaneously. Image courtesy of Rachel E. Klevit.
Flavin oxidation state impacts on nitrofuran antibiotic binding orientation in nitroreductases
Helen S. Toogood, Nigel S. Scrutton; Flavin oxidation state impacts on nitrofuran antibiotic binding orientation in nitroreductases. Biochem J 30 September 2021; 478 (18): 3423–3428. doi: https://doi.org/10.1042/BCJ20210489
Download citation file:
Sign in
Sign in to your personal account
Captcha Validation Error. Please try again.