A novel 11-kDa inhibitory subunit in the F1FO ATP synthase of Paracoccus denitrificans and related alpha-proteobacteria.

TitleA novel 11-kDa inhibitory subunit in the F1FO ATP synthase of Paracoccus denitrificans and related alpha-proteobacteria.
Publication TypeJournal Article
Year of Publication2010
AuthorsMorales-Rios, E, de la Rosa-Morales, F, Mendoza-Hernández, G, Rodríguez-Zavala, JS, Celis, H, Zarco-Zavala, M, García-Trejo, JJ
JournalFASEB J
Volume24
Issue2
Pagination599-608
Date Published2010 Feb
ISSN1530-6860
KeywordsEnzyme Inhibitors, Molecular Weight, Paracoccus denitrificans, Protein Subunits, Proton-Translocating ATPases, Rhodobacter sphaeroides
Abstract

The F(1)F(O) and F(1)-ATPase complexes of Paracoccus denitrificans were isolated for the first time by ion exchange, gel filtration, and density gradient centrifugation into functional native preparations. The liposome-reconstituted holoenzyme preserves its tight coupling between F(1) and F(O) sectors, as evidenced by its high sensitivity to the F(O) inhibitors venturicidin and diciclohexylcarbodiimide. Comparison and N-terminal sequencing of the band profile in SDS-PAGE of the F(1) and F(1)F(O) preparations showed a novel 11-kDa protein in addition to the 5 canonical alpha, beta, gamma, delta, and epsilon subunits present in all known F(1)-ATPase complexes. BN-PAGE followed by 2D-SDS-PAGE confirmed the presence of this 11-kDa protein bound to the native F(1)F(O)-ATP synthase of P. denitrificans, as it was observed after being isolated. The recombinant 11 kDa and epsilon subunits of P. denitrificans were cloned, overexpressed, isolated, and reconstituted in particulate F(1)F(O) and soluble F(1)-ATPase complexes. The 11-kDa protein, but not the epsilon subunit, inhibited the F(1)F(O) and F(1)-ATPase activities of P. denitrificans. The 11-kDa protein was also found in Rhodobacter sphaeroides associated to its native F(1)F(O)-ATPase. Taken together, the data unveil a novel inhibitory mechanism exerted by this 11-kDa protein on the F(1)F(O)-ATPase nanomotor of P. denitrificans and closely related alpha-proteobacteria.

DOI10.1096/fj.09-137356
Alternate JournalFASEB J.
Citation Key10.1096/fj.09-137356
PubMed ID19783785