CoChat
Sign Up
Cited by 188Bacterial Genetics and BiotechnologyDrug Transport and Resistance MechanismsATP Synthase and ATPases Research

The DOI matches its Crossref record; 26 of the 26 references it cites were found in a registry or an index.

The proton motive force drives the outer membrane transport of cobalamin in Escherichia coli

Open access
Bradbeer, C·1993·Journal of Bacteriology
DOI 10.1128/jb.175.10.3146-3150.1993PMC PMC204637
Open this paper in CoChat — free account

Abstract

Cells of Escherichia coli pump cobalamin (vitamin B12) across their outer membranes into the periplasmic space, and it was concluded previously that this process is potentiated by the proton motive force of the inner membrane. The novelty of such an energy coupling mechanism and its relevance to other outer membrane transport processes have required confirmation of this conclusion by studies with cells in which cobalamin transport is limited to the outer membrane. Accordingly, I have examined the effects of cyanide and of 2,4-dinitrophenol on cobalamin uptake in btuC and atp mutants, which lack inner membrane cobalamin transport and the membrane-bound ATP synthase, respectively. Dinitrophenol eliminated cobalamin transport in all strains, but cyanide inhibited this process only in atp and btuC atp mutant cells, providing conclusive evidence that cobalamin transport across the outer membrane requires specifically the proton motive force of the inner membrane. The coupling of metabolic energy to outer membrane cobalamin transport requires the TonB protein and is stimulated by the ExbB protein. I show here that the tolQ gene product can partly replace the function of the ExbB protein. Cells with mutations in both exbB and tolQ had no measurable cobalamin transport and thus had a phenotype that was essentially the same as TonB-. I conclude that the ExbB protein is a normal component of the energy coupling system for the transport of cobalamin across the outer membrane.

Overview

Integrity signals

Registry

Crossref · 10.1128/jb.175.10.3146-3150.1993

Cites

26 of 26 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Verification

Claims the paper makes

The text we found for this paper looks like another document, so its claims and self-check weren’t run. The registry and citation checks still apply.

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The text we found for this paper looks like another document, so the self-check wasn’t run.

Citations

Cites

Cited by

Sorted by citations

See all 188

Related

See all

Metadata

Authors
Bradbeer, C.
Affiliations
University of Virginia (US)
Corresponding author
Bradbeer, C
Venue
Journal of Bacteriology
Publisher
American Society for Microbiology
Published
1993-05
Volume
175
Issue
10
Pages
3146-3150
ISSN
  • 0021-9193 (ISSN-L)
  • 1098-5530
DOI
10.1128/jb.175.10.3146-3150.1993
PMC
PMC204637
OpenAlex
W1912992879
Cited by
188
References
26
Citations by year
2026: 3 · 2024: 3 · 2023: 5 · 2022: 5 · 2021: 8 · 2020: 3 · 2019: 3 · 2018: 1 · 2017: 2 · 2016: 6 · 2015: 3 · 2014: 6 · 2013: 7 · 2012: 4
FWCI
4.84
Type
journal article
Language
en
Open access
Licence
journals.asm.org/non-commercial-tdm-license (tdm)
Locations
  • Journal of Bacteriology (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
  • Health Sciences › Medicine › Oncology › Drug Transport and Resistance Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › ATP Synthase and ATPases Research
Keywords
cobalamin uptake, vitamin B12, outer membrane transport, proton motive force, Escherichia coli, TonB, ExbB, TolQ, 2,4-dinitrophenol, cyanide, energy coupling, periplasmic transport
MeSH terms
Bacterial Proteins, Biological Transport, Active, Cell Membrane, Cyanides, Dinitrophenols, Escherichia coli, Proton-Translocating ATPases, Membrane Proteins, Protons, Transduction, Genetic, Vitamin B 12, Mutagenesis, ATP-Binding Cassette Transporters, 2,4-Dinitrophenol, Escherichia coli Proteins

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review