Cation selectivity is a conserved feature in the OccD subfamily of Pseudomonas aeruginosa
| Autor: | Liviu Movileanu, Bert van den Berg, Aaron J. Wolfe, Elif Eren, Mridhu Indic, Jiaming Liu, Jagamya Vijayaraghavan |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
Subfamily
Stereochemistry The OccD subfamily Lipid Bilayers Biophysics Gating Biology medicine.disease_cause 01 natural sciences Biochemistry Article 03 medical and health sciences chemistry.chemical_compound Single-molecule biophysics Cations The OprD family 0103 physical sciences Extracellular medicine Carboxylate Cloning Molecular Lipid bilayer 030304 developmental biology 0303 health sciences 010304 chemical physics Pseudomonas aeruginosa Cell Biology Single-channel electrical recording chemistry Spontaneous gating Selectivity Bacterial outer membrane Bacterial Outer Membrane Proteins |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. (11):2908-2916 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/j.bbamem.2012.07.009 |
| Popis: | To achieve the uptake of small, water-soluble nutrients, Pseudomonas aeruginosa, a pathogenic Gram-negative bacterium, employs substrate-specific channels located within its outer membrane. In this paper, we present a detailed description of the single-channel characteristics of six members of the outer membrane carboxylate channel D (OccD) subfamily. Recent structural studies showed that the OccD proteins share common features, such as a closely related, monomeric, 18-stranded β-barrel conformation and large extracellular loops, which are folded back into the channel lumen. Here, we report that the OccD proteins displayed single-channel activity with a unitary conductance covering an unusually broad range, between 20 and 670 pS, as well as a diverse gating dynamics. Interestingly, we found that cation selectivity is a conserved trait among all members of the OccD subfamily, bringing a new distinction between the members of the OccD subfamily and the anion-selective OccK channels. Conserved cation selectivity of the OccD channels is in accord with an increased specificity and selectivity of these proteins for positively charged, carboxylate-containing substrates. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|