The pyruvate:ferredoxin oxidoreductase of the thermophilic acetogen, Thermoanaerobacter kivui

  • Pyruvate:ferredoxin oxidoreductase (PFOR) is a key enzyme in bacterial anaerobic metabolism. Since a low-potential ferredoxin (Fd2−) is used as electron carrier, PFOR allows for hydrogen evolution during heterotrophic growth as well as pyruvate synthesis during lithoautotrophic growth. The thermophilic acetogenic model bacterium Thermoanaerobacter kivui can use both modes of lifestyle, but the nature of the PFOR in this organism was previously unestablished. Here, we have isolated PFOR to apparent homogeneity from cells grown on glucose. Peptide mass fingerprinting revealed that it is encoded by pfor1. PFOR uses pyruvate as an electron donor and methylene blue (1.8 U·mg−1) and ferredoxin (Fd; 27.2 U·mg−1) as electron acceptors, and the reaction is dependent on thiamine pyrophosphate, pyruvate, coenzyme A, and Fd. The pH and temperature optima were 7.5 and 66 °C, respectively. We detected 13.6 mol of iron·mol of protein−1, consistent with the presence of three predicted [4Fe–4S] clusters. The ability to provide reduced Fd makes PFOR an interesting auxiliary enzyme for enzyme assays. To simplify and speed up the purification procedure, we established a protocol for homologous protein production in T. kivui. Therefore, pfor1 was cloned and expressed in T. kivui and the encoded protein containing a genetically engineered His-tag was purified in only two steps to apparent homogeneity. The homologously produced PFOR1 had the same properties as the enzyme from T. kivui. The enzyme can be used as auxiliary enzyme in enzymatic assays that require reduced Fd as electron donor, such as electron-bifurcating enzymes, to keep a constant level of reduced Fd.

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Author:Alexander KatsyvORCiD, Marie Charlotte Schölmerich, Mirko BasenORCiD, Volker MüllerORCiD
URN:urn:nbn:de:hebis:30:3-622300
DOI:https://doi.org/10.1002/2211-5463.13136
ISSN:2211-5463
Parent Title (English):FEBS Open Bio
Publisher:Wiley
Place of publication:Hoboken, NJ
Document Type:Article
Language:English
Date of Publication (online):2021/03/04
Date of first Publication:2021/03/04
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2021/08/30
Tag:extremophile; genetic engineering; homologous gene expression; protein production
Volume:11
Issue:5
Page Number:11
First Page:1332
Last Page:1342
Note:
We are grateful to the Deutsche Forschungsgemeinschaft (DFG) for financial support.
HeBIS-PPN:489177212
Institutes:Biowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 4.0