Salmonella typhimurium secreted invasion determinants are homologous to Shigella lpa proteins
| Autor: | Christoph J. Hueck, Vivek Bajaj, Michael J. Hantman, Catherine A. Lee, Christine Johnston, Samuel I. Miller |
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| Rok vydání: | 1995 |
| Předmět: |
Salmonella typhimurium
Transposable element Immunoblotting Molecular Sequence Data Mutant Gene Expression medicine.disease_cause Microbiology Shigella flexneri Bacterial Proteins medicine Shigella Secretion Amino Acid Sequence Molecular Biology Base Sequence biology fungi Chromosome Mapping food and beverages Chromosomes Bacterial biology.organism_classification Molecular biology Complementation Secretory protein Mutation DNA Transposable Elements Sequence Alignment Bacteria Plasmids |
| Zdroj: | Molecular Microbiology. 18:479-490 |
| ISSN: | 1365-2958 0950-382X |
| DOI: | 10.1111/j.1365-2958.1995.mmi_18030479.x |
| Popis: | Salmonella typhimurium secreted proteins (Ssp) were previously implicated in epithelial cell invasion. Here we describe four genes (SspB, sspC, sspD, and sspA), located between spaT and prgH, which encode proteins of 63, 42, 36, and 87 kDa, respectively. These Ssp are homologous to Shigella flexneri secreted proteins IpaB, IpaC, IpaD and IpaA. A non-invasive mutant with a transposon insertion in sspC lacks Ssp of 87, 42 and 36 kDa. Complementation and analyses show that sspC and sspD encode the 42 and the 36 kDa Ssp, while the 87 kDa Ssp is encoded by sspA. sspC and sspD, but not sspA, are required for invasion. Amino-terminal sequencing shows that SspC and SspA are secreted without amino-terminal processing. We further demonstrate that Ssp secretion requires proteins encoded by prgHIJK, homologous to the Shigella Ipa secretion system, since SspA is abundantly secreted by wild-type bacteria but is completely retained within the cellular fraction of a prgHIJK mutant. A precipitate containing abundant SspC and three other major Ssp of 63, 59 and 22 kDa was isolated from culture supernatants of wild-type bacteria. These data indicate that major secreted invasion determinants of S. typhimurium are structurally and functionally homolgous to S. flexneri Ipa proteins. |
| Databáze: | OpenAIRE |
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