Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India.
Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India.
Biochem Biophys Res Commun. 2019 Sep 3;516(4):1073-1077. doi: 10.1016/j.bbrc.2019.07.008. Epub 2019 Jul 4.
Mycobacterium smegmatis possesses (N,N-dimethyl-4-nitrosoaniline)-dependent (NDMA) methanol dehydrogenase (Mno) to establish methylotrophy by utilizing methanol as the source of both carbon and energy. In this study, we show that Mno forms decamer and has NADPH as the bound cofactor. Interestingly, Mno uses NDMA and not NADP as an electron acceptor in in vitro reactions. We further show that the operon mftAD required for the biosynthesis of mycofactocin, a ribosomally-synthesized electron carrier, is indispensable for the growth of M. smegmatis on methanol. Our data obtained from 2,6-Dichlorophenolindophenol reduction assays also suggest that Mno uses mycofactocin as an in vivo electron acceptor for the oxidation of methanol to formaldehyde. We thus provide here biochemical evidence for mycofactocin as an electron carrier in mycobacterial physiology.
耻垢分枝杆菌（Mycobacterium smegmatis）拥有（N,N-二甲基-4-亚硝基苯胺）依赖性（NDMA）甲醇脱氢酶（Mno），可利用甲醇作为碳源和能源来建立甲基营养型。在本研究中，我们表明 Mno 形成十聚体，并具有 NADPH 作为结合辅因子。有趣的是，Mno 在体外反应中使用 NDMA 而不是 NADP 作为电子受体。我们进一步表明，用于合成分枝杆菌因子（mycofactocin）的操纵子 mftAD 对于分枝杆菌（M. smegmatis）利用甲醇生长是必不可少的。我们从 2,6-二氯苯酚靛酚还原测定中获得的数据还表明，Mno 使用分枝杆菌因子作为体内电子受体，将甲醇氧化为甲醛。因此，我们在此提供了生物化学证据，证明分枝杆菌因子是分枝杆菌生理学中的电子载体。
