Molecular Characterization of an Outer Membrane Protein ofActinobacillus actinomycetemcomitans Belonging to the OmpA Family

ABSTRACT The major outer membrane protein (OMP) of Actinobacillus actinomycetemcomitans is an OmpA homolog that demonstrates electrophoretic heat modifiability. The gene encoding this protein was isolated from a genomic library of A. actinomycetemcomitansNCTC 9710 by immunoscreening with serum from a patient with localized juvenile periodontitis. Expression of the cloned gene inEscherichia coli and subsequent Western blot analysis revealed a protein with an approximate molecular mass of 34 kDa. The amino acid sequence predicted from the cloned gene demonstrated that the mature protein had a molecular mass of 34,911 Da and significant identity to members of the OmpA family of proteins. We have named the major OMP of A. actinomycetemcomitans Omp34, and its corresponding gene has been named omp34.

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Design, expression and functional characterization of a synthetic gene encoding the Chlamydia trachomatis major outer membrane protein

Gene ◽

10.1016/s0378-1119(00)00367-x ◽

2000 ◽

Vol 258 (1-2) ◽

pp. 173-181 ◽

Cited By ~ 9

Author(s):

H.Martin Jones ◽

Aya Kubo ◽

Richard S. Stephens

Keyword(s):

Chlamydia Trachomatis ◽

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Functional Characterization ◽

Major Outer Membrane Protein ◽

Synthetic Gene ◽

Gene Encoding

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Cloning of the Gene Encoding the Actinobacillus actinomycetemcomitans Serotype b OmpA-Like Outer Membrane Protein

Infection and Immunity ◽

10.1128/iai.67.2.942-945.1999 ◽

1999 ◽

Vol 67 (2) ◽

pp. 942-945 ◽

Cited By ~ 23

Author(s):

Hitoshi Komatsuzawa ◽

Toshihisa Kawai ◽

Mark E. Wilson ◽

Martin A. Taubman ◽

Motoyuki Sugai ◽

...

Keyword(s):

Monoclonal Antibody ◽

Amino Acid ◽

Membrane Protein ◽

Amino Acid Sequence ◽

Molecular Mass ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Actinobacillus Actinomycetemcomitans ◽

Gene Encoding ◽

Serotype B

ABSTRACT The gene encoding an outer membrane protein A (OmpA)-like, heat-modifiable Omp of Actinobacillus actinomycetemcomitans ATCC 43718 (strain Y4, serotype b) was cloned by a PCR cloning procedure. DNA sequence analysis revealed that the gene encodes a protein of 346 amino acid residues with a molecular mass of 36.9 kDa. The protein expressed by the cloned gene reacted with a monoclonal antibody to the previously described 29-kDa Omp (Omp29) of strain Y4. This monoclonal antibody reacted specifically with Omp29 of A. actinomycetemcomitans (serotype b), but not with any Omp of Escherichia coli, including OmpA. This protein exhibited characteristic heat modifiability on sodium dodecyl sulfate-polyacrylamide gels, showing an apparent molecular mass of 29 kDa when unheated and a mass of 34 kDa when heated. The N-terminal amino acid sequence of the protein expressed inE. coli perfectly matched those deduced from the purified Omp29 of strain Y4. The deduced amino acid sequence of the gene coding for Omp29 from serotype b matched completely (except for valine at position 321) that of a recently reported omp34gene described for A. actinomycetemcomitans serotype c (NCTC 9710). Because of the conserved nature of the gene within these serotypes, we designated the gene described herein from serotype b asomp34.

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