Related Experiment Video

Updated: May 9, 2026

From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
09:55

From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins

Published on: July 4, 2016

OmpC-like porin from outer membrane of Yersinia enterocolitica: molecular structure and functional activity

O P Vostrikova1, M P Isaeva, G N Likhatskaya

  • 1Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Sciences, pr. 100 let Vladivostoku 159, 690022 Vladivostok, Russia. olgavostrik@yandex.ru

Biochemistry. Biokhimiia
|July 16, 2013
PubMed

Insights

Researchers studied Yersinia enterocolitica porins, OmpC and OmpF, finding structural differences that affect their function. These outer membrane proteins show plasticity and regulated conductivity in lipid bilayers.

Area of Science:

  • Microbiology
  • Structural Biology
  • Biophysics

Background:

  • Yersinia enterocolitica outer membrane (OM) contains porin proteins crucial for nutrient transport and outer membrane integrity.
  • Porins like OmpC and OmpF exhibit significant homology across enterobacteria, suggesting conserved structural and functional roles.
  • Temperature-dependent expression of porins can influence bacterial physiology and interaction with the host environment.

Purpose of the Study:

  • To isolate and characterize the OmpC-like porin from the warm variant (37°C) of Yersinia enterocolitica.
  • To compare the physicochemical and functional properties of Y. enterocolitica OmpC and OmpF porins.
  • To analyze the structural homology and topological differences between these Y. enterocolitica porins and their Escherichia coli counterparts.

Main Methods:

  • Isolation of OmpC-like porin from Yersinia enterocolitica outer membrane.
  • Amino acid sequencing and primary structure analysis.
  • Transmembrane topology modeling based on E. coli porin models.
  • Electrophysiological studies using bilayer lipid membrane (BLM) technique.

Main Results:

  • High homology (65%) was found between Y. enterocolitica OmpC and OmpF porins, and significant homology with E. coli porins (58-76%).
  • Structural analysis revealed differences in extracellular loops and tryptophan residue positions between Y. enterocolitica OmpC and OmpF.
  • Electrophysiological data showed distinct characteristics for OmpC and OmpF channels, with OmpC exhibiting functional plasticity and potential-regulated conductivity in BLM.

Conclusions:

  • Yersinia enterocolitica OmpC and OmpF porins possess distinct molecular structures and electrophysiological properties.
  • The OmpC porin demonstrates functional plasticity and regulated channel conductivity, similar to other enterobacterial porins.
  • These findings contribute to understanding the structure-function relationships of bacterial outer membrane porins.

More Related Videos

Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification10:21

Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification

Published on: November 16, 2016

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay06:45

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay

Published on: May 26, 2011

Related Concept Videos

Structure of Porins01:21

Structure of Porins

Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a  motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel precursors...
Porin Insertion in the Outer Mitochondrial Membrane01:12

Porin Insertion in the Outer Mitochondrial Membrane

Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Gram-negative Bacterial Protein Secretion Systems01:17

Gram-negative Bacterial Protein Secretion Systems

Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
Operon Model01:23

Operon Model

The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region...
Prokaryotic Gene Structure and Organization01:28

Prokaryotic Gene Structure and Organization

Prokaryotic genomes exhibit a streamlined organization of coding and non-coding regions essential for gene expression and protein synthesis. While coding regions contain the genetic instructions for proteins or functional RNAs, non-coding regions regulate the precise transcription and translation of these genes.Coding Regions: Proteins and RNAsThe primary coding regions, known as structural genes, include sequences transcribed into messenger RNA (mRNA) and ultimately translated into...