Determination of Subunit Composition of the F₁ and F₀ Moieties of ATP Synthase from Chloroflexus aurantiacus

M. F. Yanyushin¹

¹Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, Pushchino, Moscow Region, 142292 Russia; fax: (827) 79-05-32, (7-0967) 79-05-32; E-mail: yan@issp.serpukhov.su

Submitted September 19, 1996; revision submitted December 15, 1996.

Unlike F₁-factors of standard ATP synthases of upper branches of the eubacterial dendrogram, F₁-factor of Chloroflexus aurantiacus, a representative of a lower branch of eubacteria, is not released from the bacterial membrane in low ionic strength media. An ATPase complex comprising four subunit species is released into the aqueous phase upon treatment of proteoliposomes containing reconstituted C. aurantiacus ATP synthase with chloroform. The same subunits disappear upon treatment of the proteoliposomes with 4 M NaBr, whereas five other subunits of the enzyme are still bound to the membrane. Thus, the F₁-factor of C. aurantiacus contains four subunit species and the F₀-factor contains five subunit species. Three subunits of F₀ bind [¹⁴C]DCCD.

KEY WORDS: ATP synthase, Chloroflexus aurantiacus, evolution.

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