Aerobic respiratory chain of Escherichia coli is not allowed to work in fully uncoupled mode

  • Borisov V
  • Murali R
  • Verkhovskaya M
 et al. 
  • 86

    Readers

    Mendeley users who have this article in their library.
  • 42

    Citations

    Citations of this article.

Abstract

Escherichia coli is known to couple aerobic respiratory catabolism to ATP synthesis by virtue of the primary generators of the proton motive force-NADH dehydrogenase I, cytochrome bo(3), and cytochrome bd-I. An E. coli mutant deficient in NADH dehydrogenase I, bo(3) and bd-I can, nevertheless, grow aerobically on nonfermentable substrates, although its sole terminal oxidase cytochrome bd-II has been reported to be nonelectrogenic. In the current work, the ability of cytochrome bd-II to generate a proton motive force is reexamined. Absorption and fluorescence spectroscopy and oxygen pulse methods show that in the steady-state, cytochrome bd-II does generate a proton motive force with a H(+)/e(-) ratio of 0.94 ± 0.18. This proton motive force is sufficient to drive ATP synthesis and transport of nutrients. Microsecond time-resolved, single-turnover electrometry shows that the molecular mechanism of generating the proton motive force is identical to that in cytochrome bd-I. The ability to induce cytochrome bd-II biosynthesis allows E. coli to remain energetically competent under a variety of environmental conditions.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • V. B. Borisov

  • R. Murali

  • M. L. Verkhovskaya

  • D. A. Bloch

  • H. Han

  • R. B. Gennis

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free