English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Crystal structure of Omp32, the anion-selective porin from Comamonas acidovorans, in complex with a periplasmic peptide at 2.1 angstrom resolution

Zeth, K., Diederichs, K., Welte, W., & Engelhardt, H. (2000). Crystal structure of Omp32, the anion-selective porin from Comamonas acidovorans, in complex with a periplasmic peptide at 2.1 angstrom resolution. Structure with Folding & Design, 8(9), 981-992.

Item is

Basic

show hide
Genre: Journal Article
Alternative Title : Struct. Fold. Des

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Zeth, K.1, Author              
Diederichs, K., Author
Welte, W., Author
Engelhardt, H.1, Author              
Affiliations:
1External Organizations, ou_persistent22              

Content

show
hide
Free keywords: Anion-selective ion channel; Electrophysiology; Outer membrane protein; Porin omp32; X-ray structure.; Bacterial outer membranes; Escherichia-coli; Functional-characterization; Rhodopseudomonas-blastica; Protein; Surface; Crystallography; Crystallization; Delafieldii; Sequence.; Biochemistry & Biophysics in Current Contents(R)/Life Sciences.
 Abstract: Background: Porins provide diffusion channels for salts and small organic molecules in the outer membrane of bacteria. In OmpF from Escherichia coli and related porins, an electrostatic field across the channel and a potential, originating from a surplus of negative charges, create moderate cation selectivity. Here, we investigate the strongly anion-selective porin Omp32 from Comamonas acidovorans, which is closely homologous to the porins of pathogenic Bordetella and Neisseria species. Results: The crystal structure of Omp32 was determined to a resolution of 2.1 Angstrom using single isomorphous replacement with anomalous scattering (SIRAS). The porin consists of a 16-stranded beta barrel with eight external loops and seven periplasmic turns. Loops 3 and 8, together with a protrusion located within beta-strand 2, narrow the cross-section of the pore considerably. Arginine residues create a charge filter in the constriction zone and a positive surface potential at the external and periplasmic faces. One sulfate ion was bound to Arg38 in the channel constriction zone. A peptide of 5.8 kDa appeared bound to Omp32 in a 1:1 stoichiometry on the periplasmic side close to the symmetry axis of the trimer. Eight amino acids of this peptide could be identified, revealing specific interactions with beta-strand 1 of the porin. Conclusions: The Omp32 structure explains the strong anion selectivity of this porin, Selectivity is conferred by a positive potential, which is not attenuated by negative charges inside the channel, and by an extremely narrow constriction zone. Moreover, Omp32 represents the anchor molecule for a peptide which is homologous to proteins that link the outer membrane to the cell wall peptidoglycan. [References: 48]

Details

show
hide
Language(s):
 Dates: 2000
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: eDoc: 318660
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Structure with Folding & Design
  Alternative Title : Struct. Fold. Des
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 8 (9) Sequence Number: - Start / End Page: 981 - 992 Identifier: -