Molecular Characteristics of OmpF-Like Porins from Pathogenic Yersinia

Abstract

Nonspecific pore-forming proteins (porins) are the major proteins of the outer membrane of Gram-negative bacteria responsible for diffusion of low-molecular-weight compounds. Nucleotide sequences of the OmpF-like porins from the pathogenic bacteria Yersinia pseudotuberculosis (YPS) and Yersinia enterocolitica (YE) were cloned and determined. Values of molecular weights (MW) and isoelectric points (IEP) calculated for these proteins (for OmpF-YPS: MW 37.7 kD, IEP 4.45; for OmpF-YE: MW 39.5 kD, IEP 4.34) are in good agreement with experimental data. The OmpF-like Yersinia porins are highly homologous to each other (83-92%) and also to the OmpF protein from Serratia marcescens (70%); the homology to the OmpF porin from E. coli is significantly lower (52-58%). Multiple alignment of the amino acid sequences of mature OmpF proteins provided the distribution of conservative amino acid residues typical for porins. Moreover, the OmpF-like porins from Yersinia are characterized by the presence of extended regions with high and low homologies, which coincide with the transmembrane domains and "external" loops, respectively, of the topological model of the OmpF porin from E. coli. By predictive methods, the secondary structure of the OmpF-like porins from Yersinia was obtained. This structure is represented by 16 beta-strands connected by short "periplasmic" and longer "external" loops with unordered structure.

Phenotypic and transcriptional analysis of the osmotic regulator OmpR in Yersinia pestis

“…They exist as homotrimers in the OM. The basic structural element of the porin monomer is an ellipsoid in the section cylinder consisting of 16 transmembrane β-strands (so-called β-barrel) connected by short periplasmic and longer 'external' loops [7]. …”

Immunochemical Properties of Recombinant Ompf Porin from Outer Membrane of Yersinia pseudotuberculosis

“…Therefore, the creation of polyvalent vaccine protecting from plague, intestinal yersiniosis, and pseudotuberculosis is the urgent task. The high degree of homology of Yersinia porin primary structures (Guzev et al, 2005;Likhatskaya et al, 2005;Issaeva et al, 2003) is a basis for creation of the vaccine preparations that will protect against all infections caused by pathogenic Yersinia species (Antonets et al, 2007;Portnyagina et al, 2010).…”

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

“…Based on analysis of the nucleotide sequence of the ompC gene, the amino acid sequence was obtained for the corresponding mature protein from the OM of Y. enterocolitica (denoted as OmpC_YE164). The primary structure of the porin OmpF from the OM of Y. enterocolitica determined by us earlier [30] (denominated as OmpF_YE164) was used to compare the molecular structure of porins expressed in the OM at dif ferent temperatures of Y. enterocolitica cultivation. Amino acid sequences of the OmpF and OmpC porins from E. coli (Swiss Prot bank code Q8ZG94 and GenBank code AAC75275) were used as standards [31].…”

“…The coding sequence of the ompC gene was obtained by PCR with chromosomal DNA isolated from the Y. enterocolitica strain 164 (YE164) O:3 serovar with the direct primer 5′ CAGTAGTAATCCCAGCT 3′ and with the reverse primer 5′ CTTAGAACT GATAAACCAAG 3′. The PCR was performed on an Eppendorf amplifier (Germany) in 60 mM Tris HCl buffer (pH 8.5) containing 1.5 mM MgCl 2 , 25 mM KCl, 10 mM 2 mercaptoethanol, 0.1% Triton X 100, 200 µM dNTP, the direct and reverse primers (50 pM each), and 2.5 units TagSE DNA polymerase (Sibenzyme, Russia) under the earlier described temperature regimen [30]. Results of the reaction were analyzed by electrophoresis in 1% agarose gel.…”