Kurth Julia M, Schuster Anja, Seel Waldemar, Herresthal Stefanie, Simon Jörg, Dahl Christiane
Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany.
Microbial Energy Conversion and Biotechnology, Fachbereich Biologie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany.
FEMS Microbiol Lett. 2017 Feb 1;364(3). doi: 10.1093/femsle/fnx003.
The diheme cytochromes c of the widespread TsdA family are bifunctional thiosulfate dehydrogenase/tetrathionate reductases. Here, biochemical information was collected about TsdA from the Epsilonproteobacterium Wolinella succinogenes (WsTsdA). The situation in W. succinogenes is unique since TsdA is closely associated with the unprecedented lipoprotein TsdC encoded immediately downstream of tsdA in the same direction of transcription. WsTsdA purified from Escherichia coli catalyzed both thiosulfate oxidation and tetrathionate reduction. After co-production of TsdC and WsTsdA in E. coli, TsdC was found to mediate membrane attachment of TsdA and to ensure its full catalytic activity. This effect was much stronger in the tetrathionate-reducing than in the thiosulfate-oxidizing direction. It is concluded that the TsdAC complex predominantly acts as a tetrathionate reductase in vivo.
广泛存在的TsdA家族的双血红素细胞色素c是双功能硫代硫酸盐脱氢酶/连四硫酸盐还原酶。在此，收集了有关来自埃希氏菌属琥珀酸沃林氏菌（WsTsdA）的TsdA的生化信息。琥珀酸沃林氏菌中的情况很独特，因为TsdA与前所未有的脂蛋白TsdC紧密相关，TsdC在转录的相同方向上紧接在tsdA下游编码。从大肠杆菌中纯化的WsTsdA催化硫代硫酸盐氧化和连四硫酸盐还原。在大肠杆菌中共表达TsdC和WsTsdA后，发现TsdC介导TsdA的膜附着并确保其充分的催化活性。这种作用在连四硫酸盐还原方向上比在硫代硫酸盐氧化方向上要强得多。得出的结论是，TsdAC复合物在体内主要作为连四硫酸盐还原酶起作用。
