McMillan, DGG, Jeuken, LJC, Marritt, SJ et al. (1 more author) (2012) Menaquinone-7 is specific cofactor in tetraheme quinol dehydrogenase CymA. Journal of Biological Chemistry, 287 (17). 14215 - 14225. ISSN 0021-9258
Abstract
Little is known about enzymatic quinone-quinol interconversions in the lipid membrane when compared with our knowledge of substrate transformations by globular enzymes. Here, the smallest example of a quinol dehydrogenase in nature, CymA, has been studied. CymA is a monotopic membrane tetraheme c-type cytochrome belonging to the NapC/NirT family and central to anaerobic respiration in Shewanella sp. Using protein-film electrochemistry, it is shown that vesicle-bound menaquinone-7 is not only a substrate for this enzyme but is also required as a cofactor when converting other quinones. Here, we propose that the high concentration of quinones in the membrane negates the evolutionary pressure to create a high affinity active site. However, the instability and reactivity of reaction intermediate, semiquinone, might require a cofactor that functions to minimize damaging side reactions. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This open access article is distributed under the terms of the Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Nov 2013 12:36 |
Last Modified: | 17 Jan 2018 19:30 |
Identification Number: | 10.1074/jbc.M112.348813 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76965 |