Work

Yersinia enterocolitica Type III Secretion

Year: 1999

Type: article

Abstract: Yersinia enterocolitica inject toxic proteins (effector Yops) into the cytosol of eukaryotic cells by a mechanism requiring the type III machinery. Previous work mapped a signal sufficient for the targeting of fused reporter proteins to amino acids 1-100 of YopE. Targeting requires the binding of SycE to YopE residues 15-100 in the bacterial cytoplasm. We asked whether SycE functions only to stabilize YopE in the bacterial cytoplasm, or whether the secretion chaperone itself contributes to substrate recognition by the type III machinery. Fusions of glutathione S-transferase to either the N or C terminus of SycE resulted in hybrid proteins that bound YopE but prevented targeting of the export substrate into HeLa cells. As compared with wild-type SycE, glutathione S-transferase-SycE bound and stabilized YopE in the bacterial cytoplasm but failed to release the polypeptide for export by the type III machinery. Thus, it appears that SycE functions to deliver YopE to the type III secretion machinery. A model is presented that accounts for substrate recognition of effector Yops, a group of proteins that do not share amino acid sequence or physical similarities.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.274.31.22102

Authors: Luisa W. Cheng, Olaf Schneewind

Institution: University of California, Los Angeles

Language: English

Topic: Yersinia bacterium, plague, ectoparasites research

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Institutes of Health, National Institute of Allergy and Infectious Diseases