Mycofactocin-associated mycobacterial dehydrogenases with non-exchangeable NAD cofactors
| Autor: | Stephen J. Mayclin, Thomas E. Edwards, Amy Sullivan, Bart L. Staker, Isabelle Q. H. Phan, Darren W. Begley, Anna Gardberg, Vasilios M. Marathias, Jan Abendroth, Peter J. Myler, Donald D. Lorimer, Daniel H. Haft, Phillip G. Pierce |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Models Molecular Magnetic Resonance Spectroscopy Protein Conformation Coenzymes Dehydrogenase Cyclohexane Monoterpenes Biology Crystallography X-Ray Cofactor Article 03 medical and health sciences Oxidoreductase Humans chemistry.chemical_classification Short-chain dehydrogenase Cofactor binding Multidisciplinary Binding Sites Mycobacterium tuberculosis NAD NAD binding Mutagenesis Insertional Thiazoles 030104 developmental biology Glycerol-3-phosphate dehydrogenase Biochemistry chemistry biology.protein Monoterpenes 2 6-Dichloroindophenol NAD+ kinase Oxidoreductases Protein Binding |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/srep41074 |
| Popis: | During human infection, Mycobacterium tuberculosis (Mtb) survives the normally bacteriocidal phagosome of macrophages. Mtb and related species may be able to combat this harsh acidic environment which contains reactive oxygen species due to the mycobacterial genomes encoding a large number of dehydrogenases. Typically, dehydrogenase cofactor binding sites are open to solvent, which allows NAD/NADH exchange to support multiple turnover. Interestingly, mycobacterial short chain dehydrogenases/reductases (SDRs) within family TIGR03971 contain an insertion at the NAD binding site. Here we present crystal structures of 9 mycobacterial SDRs in which the insertion buries the NAD cofactor except for a small portion of the nicotinamide ring. Line broadening and STD-NMR experiments did not show NAD or NADH exchange on the NMR timescale. STD-NMR demonstrated binding of the potential substrate carveol, the potential product carvone, the inhibitor tricyclazol, and an external redox partner 2,6-dichloroindophenol (DCIP). Therefore, these SDRs appear to contain a non-exchangeable NAD cofactor and may rely on an external redox partner, rather than cofactor exchange, for multiple turnover. Incidentally, these genes always appear in conjunction with the mftA gene, which encodes the short peptide MftA, and with other genes proposed to convert MftA into the external redox partner mycofactocin. |
| Databáze: | OpenAIRE |
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