1. The Biological Role of the ζ Subunit as Unidirectional Inhibitor of the F 1 F O -ATPase of Paracoccus denitrificans.
- Author
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Mendoza-Hoffmann F, Pérez-Oseguera Á, Cevallos MÁ, Zarco-Zavala M, Ortega R, Peña-Segura C, Espinoza-Simón E, Uribe-Carvajal S, and García-Trejo JJ
- Subjects
- Ion Transport genetics, Mitochondria metabolism, Paracoccus denitrificans growth & development, Protein Subunits genetics
- Abstract
The biological roles of the three natural F
1 FO -ATPase inhibitors, ε, ζ, and IF1 , on cell physiology remain controversial. The ζ subunit is a useful model for deletion studies since it mimics mitochondrial IF1 , but in the F1 FO -ATPase of Paracoccus denitrificans (PdF1 FO ), it is a monogenic and supernumerary subunit. Here, we constructed a P. denitrificans 1222 derivative (PdΔζ) with a deleted ζ gene to determine its role in cell growth and bioenergetics. The results show that the lack of ζ in vivo strongly restricts respiratory P. denitrificans growth, and this is restored by complementation in trans with an exogenous ζ gene. Removal of ζ increased the coupled PdF1 FO -ATPase activity without affecting the PdF1 FO -ATP synthase turnover, and the latter was not affected at all by ζ reconstitution in vitro. Therefore, ζ works as a unidirectional pawl-ratchet inhibitor of the PdF1 FO -ATPase nanomotor favoring the ATP synthase turnover to improve respiratory cell growth and bioenergetics., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2018
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