We discovered a new small non-coding RNA (sRNA) gene, vrrA of Vibrio cholerae O1 strain A1552. A vrrA mutant overproduces OmpA porin, and we demonstrate that the 140 nt VrrA RNA represses ompA translation by base-pairing with the 5' region of the mRNA. The RNA chaperone Hfq is not stringently required for VrrA action, but expression of the vrrA gene requires the membrane stress sigma factor, si...

The major outer membrane protein patterns of 45 Escherichia coli strains of human origin were compared with that of E. coli K12 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Preparations of the former strains contained between two and five major bands in the molecular weight range between 30 000 and 42 000. The patterns were very heterogeneous with respect to the numbers and el...

The cloning and sequencing of the Brucella abortus major 25-kDa outer membrane protein (OMP) is reported. The 25-kDa (group 3) OMP has been proposed, on the basis of amino acid composition, to be the counterpart of OmpA (D. R. Verstraete, M. T. Creasy, N. T. Caveney, C. L. Baldwin, M. W. Blab, and A. J. Winter, Infect. Immun. 35:979-989, 1982). However, the amino acid sequence predicted from th...

Outer membrane protein A (OmpA) of Escherichia coli is a beta-barrel membrane protein that unfolds in 8 M urea to a random coil. OmpA refolds upon urea dilution in the presence of certain detergents or lipids. To examine the minimal requirements for secondary and tertiary structure formation in beta-barrel membrane proteins, folding of OmpA was studied as a function of the hydrophobic chain len...

Shigella flexneri is an intracellular pathogen that deploys an arsenal of virulence factors promoting host cell invasion, intracellular multiplication and intra- and inter-cellular dissemination. We have previously reported that the interaction between apyrase (PhoN2), a periplasmic ATP-diphosphohydrolase, and the C-terminal domain of the outer membrane (OM) protein OmpA is likely required for ...

Membrane protein insertion and folding was studied for the major outer membrane protein of Fusobacterium nucleatum (FomA), which is a voltage-dependent general diffusion porin. The transmembrane domain of FomA forms a beta-barrel that is predicted to consist of 14 beta-strands. Here, unfolded FomA is shown to insert and fold spontaneously and quantitatively into phospholipid bilayers upon dilut...

avian pasteurella multocida is an agent of fowl cholera. the protective effect achieved through orthodoxvaccines is not ideal. the research on novel vaccines against avian pasteurella multocida is imperative. inthis study, the genes encoding outer membrane protein h and a (omph and ompa) were cloned into theeukaryotic expression vector pcdna3.1(+) and the recombinant plasmids, namely dna vaccin...

Molecular dynamics (MD) simulations are used to explore the dynamics of a membrane protein in its crystal environment. A 50-ns-duration simulation (at a temperature of 300 K) is performed for the crystallographic unit cell of the bacterial outer membrane protein OmpA. The unit cell contains four protein molecules, plus detergent molecules and water. An excellent correlation between simulated an...

Avian Pasteurella multocida is an agent of fowl cholera. The protective effect achieved through orthodoxvaccines is not ideal. The research on novel vaccines against avian Pasteurella multocida is imperative. Inthis study, the genes encoding outer membrane protein H and A (OmpH and OmpA) were cloned into theeukaryotic expression vector pcDNA3.1(+) and the recombinant plasmids, namely DNA vaccin...

Anaplasma phagocytophilum is the tick-transmitted obligate intracellular bacterium that causes human granulocytic anaplasmosis (HGA). A. phagocytophilum binding to sialyl Lewis x (sLe(x)) and other sialylated glycans that decorate P selectin glycoprotein 1 (PSGL-1) and other glycoproteins is critical for infection of mammalian host cells. Here, we demonstrate the importance of A. phagocytophilu...