ATP synthase that lacks F0a-subunit: isolation, properties, and indication of F0b2-subunits as an anchor rail of a rotating c-ring

In a rotary motor F1F0-ATP synthase, F0 works as a proton motor; the oligomer ring of F0c-subunits (c-ring) rotates relative to the F0ab2 domain as protons pass through F0 down the gradient. F0ab2 must exert dual functions during rotation, that is, sliding the c-ring (motor drive) while keeping the...

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Veröffentlicht in:The Journal of biological chemistry 2004-08, Vol.279 (32), p.33409-33412
Hauptverfasser: Ono, Sakurako, Sone, Nobuhito, Yoshida, Masasuke, Suzuki, Toshiharu
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Sprache:eng
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Zusammenfassung:In a rotary motor F1F0-ATP synthase, F0 works as a proton motor; the oligomer ring of F0c-subunits (c-ring) rotates relative to the F0ab2 domain as protons pass through F0 down the gradient. F0ab2 must exert dual functions during rotation, that is, sliding the c-ring (motor drive) while keeping the association with the c-ring (anchor rail). Here we have isolated thermophilic F1F0(-a) which lacks F0a. F1F0(-a) has no proton transport activity, and F0(-a) does not work as a proton channel. Interestingly, ATPase activity of F1F0(-a) is greatly suppressed, even though its F1 sector is intact. Most likely, F0b2 associates with the c-ring as an anchor rail in the intact F1F0; without F0a, this association prevents rotation of the c-ring (and hence the gamma-subunit), which disables ATP hydrolysis at F1. Functional F1F0 is easily reconstituted from purified F0a and F1F0(-a), and thus F0a can bind to its proper location on F1F0(-a) without a large rearrangement of other-subunits.
ISSN:0021-9258
DOI:10.1074/jbc.M404993200