Protein–protein interaction regulates the direction of catalysis and electron transfer in a redox enzyme complex

McMillan, Duncan G. G., Marritt, Sophie J., Firer-Sherwood, Mackenzie A., Shi, Liang, Richardson, David J. ORCID: https://orcid.org/0000-0002-6847-1832, Evans, Stephen D., Elliott, Sean J., Butt, Julea N. ORCID: https://orcid.org/0000-0002-9624-5226 and Jeuken, Lars J. C. (2013) Protein–protein interaction regulates the direction of catalysis and electron transfer in a redox enzyme complex. Journal of the American Chemical Society, 135 (28). pp. 10550-10556. ISSN 0002-7863

Full text not available from this repository. (Request a copy)

Abstract

Protein–protein interactions are well-known to regulate enzyme activity in cell signaling and metabolism. Here, we show that protein–protein interactions regulate the activity of a respiratory-chain enzyme, CymA, by changing the direction or bias of catalysis. CymA, a member of the widespread NapC/NirT superfamily, is a menaquinol-7 (MQ-7) dehydrogenase that donates electrons to several distinct terminal reductases in the versatile respiratory network of Shewanella oneidensis. We report the incorporation of CymA within solid-supported membranes that mimic the inner membrane architecture of S. oneidensis. Quartz-crystal microbalance with dissipation (QCM-D) resolved the formation of a stable complex between CymA and one of its native redox partners, flavocytochrome c3 (Fcc3) fumarate reductase. Cyclic voltammetry revealed that CymA alone could only reduce MQ-7, while the CymA-Fcc3 complex catalyzed the reaction required to support anaerobic respiration, the oxidation of MQ-7. We propose that MQ-7 oxidation in CymA is limited by electron transfer to the hemes and that complex formation with Fcc3 facilitates the electron-transfer rate along the heme redox chain. These results reveal a yet unexplored mechanism by which bacteria can regulate multibranched respiratory networks through protein–protein interactions.

Item Type:	Article
Faculty \ School:	Faculty of Science > School of Chemistry Faculty of Science > School of Biological Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Organisms and the Environment Faculty of Science > Research Groups > Molecular Microbiology Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry Faculty of Science > Research Groups > Biophysical Chemistry (former - to 2017) Faculty of Science > Research Groups > Chemistry of Light and Energy Faculty of Science > Research Groups > Chemistry of Life Processes Faculty of Science > Research Groups > Energy Materials Laboratory
Depositing User:	Pure Connector
Date Deposited:	30 Jul 2013 02:24
Last Modified:	06 Jun 2023 09:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/43095
DOI:	10.1021/ja405072z

Actions (login required)

View Item