Infect. Immun., Jan 1995, 1-8, Vol 63, No. 1
SM Kulich, DW Frank and JT Barbieri
The structural gene for the 49-kDa form of exoenzyme S (exoS) isolated from
Pseudomonas aeruginosa 388 was expressed in both Escherichia coli and P.
aeruginosa PA103. Expression of exoS in E. coli under the transcriptional
regulation of the T7 promoter yielded a soluble cytosolic protein with an
apparent molecular mass of 49 kDa, as determined by sodium dodecyl
sulfate-polyacrylamide gel electrophoresis. Expression of exoS in P.
aeruginosa PA103 under the transcriptional regulation of the 0.9 kbp of
Pseudomonas chromosomal DNA flanking the 5' end of exoS yielded a
nitrilotriacetic acid- inducible extracellular protein with an apparent
molecular mass of 49 kDa. Recombinant ExoS (rExoS) reacted with the
anti-49-kDa form of exoenzyme S immunoglobulin G, existed as an aggregate
as determined by gel filtration chromatography, and ADP-ribosylated soybean
trypsin inhibitor at a specific activity that was similar (within twofold)
to that of native exoenzyme S. Allelic exchange of exoS with a tetracycline
gene cartridge yielded a strain of P. aeruginosa 388 that did not express
detectable amounts of either ExoS in an immunoblot analysis using the
anti-49-kDa form of exoenzyme S immunoglobulin G or ADP-ribosyltransferase
activity under standard enzyme assay conditions. Expression of
catalytically active rExoS in E. coli demonstrated that exoS was necessary
and sufficient for the factor-activating exoenzyme S- dependent
ADP-ribosyltransferase activity of exoenzyme S. Expression of
nitrilotriacetic acid-inducible rExoS in P. aeruginosa PA103 demonstrated
that the 0.9 kbp of Pseudomonas chromosomal DNA flanking the 5' end of exoS
encoded a functional exoenzyme S promoter. Expression analysis and allelic
exchange experiments suggest that the 49- and 53-kDa forms of exoenzyme S
are encoded by separate genes.
Copyright © 1995, American Society for Microbiology
Expression of recombinant exoenzyme S of Pseudomonas aeruginosa
Department of Microbiology, Medical College of Wisconsin, Milwaukee 53226.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|