Understanding Voltage Gating of Providencia stuartii Porins at Atomic Level

Song, Wanling; Bajaj, Harsha; Nasrallah, Chady; Jiang, Hualiang; Winterhalter, Mathias; Colletier, J.P.; Xu, Yechun

doi:10.1371/journal.pcbi.1004255

Cited by 10 publications

(13 citation statements)

References 59 publications

(72 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Calculation of the electrostatic potential along the Omp-Pst2 channel furthermore suggests a facilitated transport of cations from the intracellular to the extracellular side of the porin ( Fig. 1 J and L), in line with recent MD simulations based on the structure (15). We note that as in Omp-Pst1 crystals, no contact is observed between intracellular turns of Omp-Pst2, and a cavity is apparent at the center of the trimeric complex.…”

Section: Resultssupporting

confidence: 89%

“…The electrostatic potential profile calculated along the channel of Omp-Pst1 indicates mild anion selectivity ( Fig. 1L), in line with electrophysiology measurements and with molecular dynamics (MD) simulations based on this structure (15). Nevertheless, the Omp-Pst1 channel features more charged residues than E. coli porins (48%, 35%, and 20% more charged residues than OmpF, OmpC, and PhoE, respectively), suggesting higher translocation selectivity.…”

Section: Resultssupporting

confidence: 80%

“…1L and SI Appendix, Fig. S2D), which has been verified by electrophysiology measurements (15). Calculation of the electrostatic potential along the Omp-Pst2 channel furthermore suggests a facilitated transport of cations from the intracellular to the extracellular side of the porin ( Fig.…”

Section: Resultssupporting

confidence: 60%

See 2 more Smart Citations

Porin self-association enables cell-to-cell contact in Providencia stuartii floating communities

El-Khatib

Nasrallah

Lopes

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

The gram-negative pathogen forms floating communities within which adjacent cells are in apparent contact, before depositing as canonical surface-attached biofilms. Because porins are the most abundant proteins in the outer membrane of gram-negative bacteria, we hypothesized that they could be involved in cell-to-cell contact and undertook a structure-function relationship study on the two porins of, Omp-Pst1 and Omp-Pst2. Our crystal structures reveal that these porins can self-associate through their extracellular loops, forming dimers of trimers (DOTs) that could enable cell-to-cell contact within floating communities. Support for this hypothesis was obtained by studying the porin-dependent aggregation of liposomes and model cells. The observation that facing channels are open in the two porin structures suggests that DOTs could not only promote cell-to-cell contact but also contribute to intercellular communication.

show abstract

Section: Resultssupporting

confidence: 89%

Section: Resultssupporting

confidence: 80%

See 1 more Smart Citation

Porin self-association enables cell-to-cell contact in Providencia stuartii floating communities

El-Khatib

Nasrallah

Lopes

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…stuartii predominantly expresses Omp-Pst1, and it was proposed that Omp-Pst1 is the major porin of the bacterium [40]. Electrophysiology measurements revealed that Omp-Pst2 is highly cation-selective and prone to voltage-gating (critical voltage Vc = 20–90 mV), whereas Omp-Pst1 channel gates normally (Vc > 199 mV), is mildly anion selective and comparatively more permissive to β-lactam antibiotics [40,41]. MD simulations suggested that Omp-Pst2 atypical voltage-gating behaviour is asymmetric and triggered by the influx of cations from the extracellular to the periplasmic side of the porin.…”

Section: Introductionmentioning

confidence: 99%

Providencia stuartii form biofilms and floating communities of cells that display high resistance to environmental insults

Khatib¹,

Tran²,

Nasrallah³

et al. 2017

PLoS ONE

Self Cite

View full text Add to dashboard Cite

Biofilms are organized communities of bacterial cells that are responsible for the majority of human chronic bacterial infections. Providencia stuartii is a Gram-negative biofilm-forming bacterium involved in high incidence of urinary tract infections in catheterized patients. Yet, the structuration of these biofilms, and their resistance to environmental insults remain poorly understood. Here, we report on planktonic cell growth and biofilm formation by P. stuartii, in conditions that mimic its most common pathophysiological habitat in humans, i.e. the urinary tract. We observed that, in the planktonic state, P. stuartii forms floating communities of cells, prior to attachment to a surface and subsequent adoption of the biofilm phenotype. P. stuartii planktonic and biofilm cells are remarkably resistant to calcium, magnesium and to high concentrations of urea, and show the ability to grow over a wide range of pHs. Experiments conducted on a P. stuartii strain knocked-out for the Omp-Pst2 porin sheds light on the role it plays in the early stages of growth, as well as in the adaptation to high concentration of urea and to varying pH.

show abstract

“…With regard to the biological function of these channel properties, various hypotheses are put forward. In particular, this may be due to the closing of the channels of improperly incorporated proteins and may also be the protective (as the medium pH decreases) or even regulatory transport function of porins (e.g., in proteins with a very low critical channel closure voltage, Vc) [15, 16]. However, all the proposed explanations are not sufficiently convincing and, perhaps, this property may be considered only as an unusual artifact [17].…”

Section: Introductionmentioning

confidence: 99%

An Abnormally High Closing Potential of the OMPF Porin Channel from Yersinia Ruckeri: The Role of Charged Residues and Intramolecular Bonds

et al. 2019

View full text Add to dashboard Cite

Electrophysiological experiments on bilayer lipid membranes showed that the isolated outer membrane major porin of Yersinia ruckeri (YrOmpF) exhibits activity typical of porins from Gram-negative bacteria, forming channels with a mean conductance of 230 pS (in 0.1 M KCl) and slight asymmetry with respect to the applied voltage. Under acidic conditions (up to pH = 3.0), there was no significant decrease in the total conductance of the YrOmpF channel reconstituted into the bilayer. The studied channel significantly differed from the porins of other bacteria by high values of its critical closing potential (Vc): Vc = 232 mV at pH = 7.0 and Vc = 164 mV at pH = 5.0. A theoretical model of the YrOmpF spatial structure was used for the analysis of the charge distribution in the mouth and inside the channel to explain these properties and quantitatively assess the bonds between the amino acid residues in the L3 loop and on the inner wall of the barrel. The parameters of YrOmpF were compared with those of the classical OmpF porin from E. coli. The results of electrophysiological experiments and theoretical analysis are discussed in terms of the mechanism for voltage-dependent closing of porin channels.

show abstract

Understanding Voltage Gating of Providencia stuartii Porins at Atomic Level

Cited by 10 publications

References 59 publications

Porin self-association enables cell-to-cell contact in Providencia stuartii floating communities

Porin self-association enables cell-to-cell contact in Providencia stuartii floating communities

Providencia stuartii form biofilms and floating communities of cells that display high resistance to environmental insults

An Abnormally High Closing Potential of the OMPF Porin Channel from Yersinia Ruckeri: The Role of Charged Residues and Intramolecular Bonds

Contact Info

Product

Resources

About