Open AccessC‐terminal regulatory domain of the ε subunit of F o F 1 ATP synthase enhances the ATP‐dependent H + pumping that is involved in the maintenance of cellular membrane potential in Bacillus subtilis
Author(s) -
Akanuma Genki,
Tagana Tomoaki,
Sawada Maho,
Suzuki Shota,
Shimada Tomohiro,
Tanaka Kan,
Kawamura Fujio,
KatoYamada Yasuyuki
Publication year - 2019
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.815
Subject(s) - atp synthase , mutant , protein subunit , biology , bacillus subtilis , atpase , operon , atp synthase gamma subunit , mutation , microbiology and biotechnology , biochemistry , enzyme , gene , bacteria , genetics , atp hydrolysis
The ε subunit of F o F 1 ‐ATPase/synthase (F o F 1 ) plays a crucial role in regulating F o F 1 activity. To understand the physiological significance of the ε subunit‐mediated regulation of F o F 1 in Bacillus subtilis , we constructed and characterized a mutant harboring a deletion in the C‐terminal regulatory domain of the ε subunit (ε ∆C ). Analyses using inverted membrane vesicles revealed that the ε ∆C mutation decreased ATPase activity and the ATP‐dependent H + ‐pumping activity of F o F 1 . To enhance the effects of ε ∆C mutation, this mutation was introduced into a ∆ rrn8 strain harboring only two of the 10 rrn (rRNA) operons (∆ rrn8 ε ∆C mutant strain). Interestingly, growth of the ∆ rrn8 ε ∆C mutant stalled at late‐exponential phase. During the stalled growth phase, the membrane potential of the ∆ rrn8 ε ∆C mutant cells was significantly reduced, which led to a decrease in the cellular level of 70S ribosomes. The growth stalling was suppressed by adding glucose into the culture medium. Our findings suggest that the C‐terminal region of the ε subunit is important for alleviating the temporal reduction in the membrane potential, by enhancing the ATP‐dependent H + ‐pumping activity of F o F 1 .