The structures of E. coli NfsA bound to the antibiotic nitrofurantoin; to 1,4-benzoquinone and to FMN
| Autor: | Antonio E Graziano, Martin A Day, Peter F. Searle, Andrew J. Christofferson, J. L. Ross Anderson, David Jarrom, Eva I. Hyde, Scott A. White |
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| Rok vydání: | 2021 |
| Předmět: |
Conformational change
Semiquinone Flavin Mononucleotide Stereochemistry Flavoprotein Molecular Dynamics Simulation Crystallography X-Ray Biochemistry Cofactor Substrate Specificity 1 4-Benzoquinone 03 medical and health sciences chemistry.chemical_compound Nitroreductase Protein Domains Benzoquinones Escherichia coli Molecular Biology 030304 developmental biology 0303 health sciences Binding Sites Molecular Structure biology Ligand Escherichia coli Proteins 030302 biochemistry & molecular biology Active site Cell Biology Nitroreductases Anti-Bacterial Agents Kinetics Nitrofurantoin chemistry Biocatalysis biology.protein Oxidation-Reduction NADP Protein Binding |
| Zdroj: | 'Biochemical Journal ', vol: 478, pages: 2601-2617 (2021) Day, M A, Jarrom, D, Christofferson, A J, Graziano, A E, Anderson, J L R, Searle, P F, Hyde, E I & White, S A 2021, ' The structures of E. coli NfsA bound to the antibiotic nitrofurantoin; to 1,4-benzoquinone and to FMN ', Biochemical Journal, vol. 478, no. 13, pp. 2601-2617 . https://doi.org/10.1042/BCJ20210160 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bcj20210160 |
| Popis: | NfsA is a dimeric flavoprotein that catalyses the reduction in nitroaromatics and quinones by NADPH. This reduction is required for the activity of nitrofuran antibiotics. The crystal structure of free Escherichia coli NfsA and several homologues have been determined previously, but there is no structure of the enzyme with ligands. We present here crystal structures of oxidised E. coli NfsA in the presence of several ligands, including the antibiotic nitrofurantoin. Nitrofurantoin binds with the furan ring, rather than the nitro group that is reduced, near the N5 of the FMN. Molecular dynamics simulations show that this orientation is only favourable in the oxidised enzyme, while potentiometry suggests that little semiquinone is formed in the free protein. This suggests that the reduction occurs by direct hydride transfer from FMNH− to nitrofurantoin bound in the reverse orientation to that in the crystal structure. We present a model of nitrofurantoin bound to reduced NfsA in a viable hydride transfer orientation. The substrate 1,4-benzoquinone and the product hydroquinone are positioned close to the FMN N5 in the respective crystal structures with NfsA, suitable for reaction, but are mobile within the active site. The structure with a second FMN, bound as a ligand, shows that a mobile loop in the free protein forms a phosphate-binding pocket. NfsA is specific for NADPH and a similar conformational change, forming a phosphate-binding pocket, is likely to also occur with the natural cofactor. |
| Databáze: | OpenAIRE |
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