The omp2 gene locus of Brucella abortus encodes two homologous outer membrane proteins with properties characteristic of bacterial porins

Author:

Marquis H1,Ficht T A1

Affiliation:

1. Department of Veterinary Pathobiology, Texas Veterinary Medical Center, Texas A&M University, College Station 77843-4467.

Abstract

In Brucella abortus, a gene encoding a major cell envelope protein, omp2, is duplicated within a short segment of the large chromosomal DNA. Although both genes contain open reading frames, encoding proteins of high identity, expression from only one, omp2b, has been detected in laboratory-grown B. abortus. In the present study, we wished to determine whether omp2b encodes the previously studied Brucella porin and to characterize the omp2a gene product. Experiments were performed with Escherichia coli transformants expressing either omp2a or omp2b. Our results indicated that both gene products localized to the outer membrane of E. coli. Initial rates of transport of [14C]maltose and growth rates in the presence of maltodextrins of defined size indicated an increased hydrophilic permeability of transformants expressing omp2a. These cells were also shown to grow on maltotetraose, a molecule with a molecular mass of 667 Da. Activity consistent with the formation of pores could not be demonstrated in transformants expressing omp2b. However, Omp2b formed oligomers resistant to heat denaturation up to 70 degrees C in sodium dodecyl sulfate buffer, a property characteristic of bacterial porins. Overall, these results suggest that the omp2a gene product has pore-forming activity and that the omp2b gene encodes the previously characterized Brucella porin.

Publisher

American Society for Microbiology

Subject

Infectious Diseases,Immunology,Microbiology,Parasitology

Reference37 articles.

1. Isolation and characterization of outer membrane permeability mutants in Escherichia coli K-12;Benson S. A.;J. Bacteriol.,1985

2. Structure and function of porins from Gramnegative bacteria. Annu;Benz R.;Rev. Microbiol.,1988

3. A rapid, sensitive method for detection of alkaline phosphatase-conjugated antibody on Western blots;Blake M. S.;Anal. Biochem.,1984

4. The cell envelope of Gram-negative bacteria: new aspects of its function in transport and chemotaxis;Brass J. M.;Curr. Top. Microbiol. Immunol.,1986

5. Reconstitution of maltose transport in maIB mutants of Escherichia coli through calcium-induced disruptions of the outer membrane;Brass J. M.;J. Bacteriol.,1981

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