Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2016 Aug 8;7:12387. doi: 10.1038/ncomms12387

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2016, The Author(s)

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

PMC Copyright notice

(a–d) Ethidium transport in DNA-loaded empty liposomes (a) or proteoliposomes containing the MsbA-DED triple mutant (b), MsbA-WT (c) or MsbA-MD (d) with imposed ΔpH (pH_in 6.8/pH_out 8.0), Δψ (interior positive), proton-motive force ( in which Z equals ∼58 mV at 20 °C), ΔpH_REV (pH_in 8.0/pH_out 6.8), or in the absence of ion gradients (pH_in 6.8/pH_out 6.8, termed No gradient and pH_in 8.0/pH_out 8.0, No gradient 8/8). No gradient 8/8 for (a,b,d) was very close to the No gradient control, and is not shown for clarity of presentation. The 5-fold accumulation of ethidium by MsbA-WT is indicated in the fluorescence versus time graph in (c). (e,f) Effect of the imposition of a reversed Δψ_REV (interior negative) without or with the ΔpH (interior acidic) () on ethidium transport in proteoliposomes containing MsbA-WT (e) or empty liposomes (f). Data represent observations in three or more independent experiments with independently prepared batches of proteoliposomes. Values in histograms show significance of fluorescence levels at steady-state, and are expressed as mean±s.e.m. (one-way analysis of variance; *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001).

Inline graphic — (a–d) Ethidium transport in DNA-loaded empty liposomes (a) or proteoliposomes containing the MsbA-DED triple mutant (b), MsbA-WT (c) or MsbA-MD (d) with imposed ΔpH (pH_in 6.8/pH_out 8.0), Δψ (interior positive), proton-motive force ( in which Z equals ∼58 mV at 20 °C), ΔpH_REV (pH_in 8.0/pH_out 6.8), or in the absence of ion gradients (pH_in 6.8/pH_out 6.8, termed No gradient and pH_in 8.0/pH_out 8.0, No gradient 8/8). No gradient 8/8 for (a,b,d) was very close to the No gradient control, and is not shown for clarity of presentation. The 5-fold accumulation of ethidium by MsbA-WT is indicated in the fluorescence versus time graph in (c). (e,f) Effect of the imposition of a reversed Δψ_REV (interior negative) without or with the ΔpH (interior acidic) () on ethidium transport in proteoliposomes containing MsbA-WT (e) or empty liposomes (f). Data represent observations in three or more independent experiments with independently prepared batches of proteoliposomes. Values in histograms show significance of fluorescence levels at steady-state, and are expressed as mean±s.e.m. (one-way analysis of variance; *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001).