pKa of the essential Glu54 and backbone conformation for subunit c from the H+-coupled F1F0 ATP synthase from an alkaliphilic Bacillus

FEBS Letters
Iván O Rivera-TorresMark E Girvin

Abstract

The conformation of the ATP synthase c-subunit and the pKa of its essential E54 residue were characterized in alkaliphilic Bacillus pseudofirmus OF4. The c-subunit folds as a helix-loop-helix, with inter-helical contacts demonstrated by paramagnetic relaxation effects. The E54 pKa of 7.7 is significantly higher than in non-alkaliphiles, which likely prevents proton loss from the c-rotor at high pH. The E54 pKa was unchanged in a mutant, cP51A, that has a severe ATP synthesis defect at high pH only. cP51 must have some structural role that accounts for the mutant defect, such as different subunit-subunit interactions at high pH.

References

May 1, 1994·Journal of Magnetic Resonance. Series B·L YuS W Fesik
Nov 1, 1995·Journal of Biomolecular NMR·F DelaglioA Bax
Jun 17, 1998·Proceedings of the National Academy of Sciences of the United States of America·W Jiang, R H Fillingame
Nov 27, 1999·Science·D StockJ E Walker
Dec 15, 2000·Current Opinion in Structural Biology·D StockJ E Walker
Nov 25, 2003·FEBS Letters·Robert H FillingameOleg Y Dmitriev
Sep 1, 1994·Journal of Biomolecular NMR·B A Johnson, R A Blevins

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