TY  - JOUR
A1  - Juhnke, Hanno Dominik
A1  - Hiltscher, Heiko
A1  - Nasiri, Hamid Reza
A1  - Schwalbe, Harald
A1  - Lancaster, C. Roy D.
T1  - Production, characterization and determination of the real catalytic properties of the putative "succinate dehydrogenase" from Wolinella succinogenes
T2  - Molecular microbiology
N2  - Both the genomes of the epsilonproteobacteria Wolinella succinogenes and Campylobacter jejuni contain operons (sdhABE) that encode for so far uncharacterized enzyme complexes annotated as ‘non-classical’ succinate:quinone reductases (SQRs). However, the role of such an enzyme ostensibly involved in aerobic respiration in an anaerobic organism such as W. succinogenes has hitherto been unknown. We have established the first genetic system for the manipulation and production of a member of the non-classical succinate:quinone oxidoreductase family. Biochemical characterization of the W. succinogenes enzyme reveals that the putative SQR is in fact a novel methylmenaquinol:fumarate reductase (MFR) with no detectable succinate oxidation activity, clearly indicative of its involvement in anaerobic metabolism. We demonstrate that the hydrophilic subunits of the MFR complex are, in contrast to all other previously characterized members of the superfamily, exported into the periplasm via the twin-arginine translocation (tat)-pathway. Furthermore we show that a single amino acid exchange (Ala86→His) in the flavoprotein of that enzyme complex is the only additional requirement for the covalent binding of the otherwise non-covalently bound FAD. Our results provide an explanation for the previously published puzzling observation that the C. jejuni sdhABE operon is upregulated in an oxygen-limited environment as compared with microaerophilic laboratory conditions.
Y1  - 2009
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/27278
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-272782
SN  - 1088–1101
SN  - 1365-2958
N1  - Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.
VL  - 71
IS  - 5
SP  - 1088
EP  - 1101
PB  - Wiley-Blackwell
CY  - Oxford [u.a.]
ER  -