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Crystal Structure of the Salmonella Typhimurium Effector GtgE
Salmonella Typhimurium GtgE is an effector protein contributing to the virulence of this pathogen. It was shown to possess highly selective proteolytic activity against a subset of Rab proteins that helps in evasion of Salmonella-containing vacuole (SCV) fusion with lysosomes. Cys45, His151 and Asp1...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5140068/ https://www.ncbi.nlm.nih.gov/pubmed/27923041 http://dx.doi.org/10.1371/journal.pone.0166643 |
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author | Xu, Caishuang Kozlov, Guennadi Wong, Kathy Gehring, Kalle Cygler, Miroslaw |
author_facet | Xu, Caishuang Kozlov, Guennadi Wong, Kathy Gehring, Kalle Cygler, Miroslaw |
author_sort | Xu, Caishuang |
collection | PubMed |
description | Salmonella Typhimurium GtgE is an effector protein contributing to the virulence of this pathogen. It was shown to possess highly selective proteolytic activity against a subset of Rab proteins that helps in evasion of Salmonella-containing vacuole (SCV) fusion with lysosomes. Cys45, His151 and Asp169 are essential for proteolytic activity. The structure of a C-terminal fragment GtgE(79–214) indicated the presence of a papain-like fold. Here, we present the structure of GtgE(17–214) containing the fully assembled active site. The design of a proteolytically active and crystallizable GtgE construct was aided by NMR spectroscopy. The protein indeed displays papain-like fold with an assembled Cys-His-Asp catalytic triad. Like the full-length GtgE, the crystallizable construct showed low activity in vitro for its known substrates, Rab32 and Rab29. NMR titration experiments showed at most very weak binding of GtgE to the peptide encompassing the Rab29 cleavage site. In view of the low in vitro activity and poor substrate binding, we postulate that the function of GtgE in vivo as a proteolytic enzyme is dependent on other factor(s), such as a protein partner or interactions with the SCV membrane, which stimulate(s) GtgE activity in vivo. |
format | Online Article Text |
id | pubmed-5140068 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-51400682016-12-21 Crystal Structure of the Salmonella Typhimurium Effector GtgE Xu, Caishuang Kozlov, Guennadi Wong, Kathy Gehring, Kalle Cygler, Miroslaw PLoS One Research Article Salmonella Typhimurium GtgE is an effector protein contributing to the virulence of this pathogen. It was shown to possess highly selective proteolytic activity against a subset of Rab proteins that helps in evasion of Salmonella-containing vacuole (SCV) fusion with lysosomes. Cys45, His151 and Asp169 are essential for proteolytic activity. The structure of a C-terminal fragment GtgE(79–214) indicated the presence of a papain-like fold. Here, we present the structure of GtgE(17–214) containing the fully assembled active site. The design of a proteolytically active and crystallizable GtgE construct was aided by NMR spectroscopy. The protein indeed displays papain-like fold with an assembled Cys-His-Asp catalytic triad. Like the full-length GtgE, the crystallizable construct showed low activity in vitro for its known substrates, Rab32 and Rab29. NMR titration experiments showed at most very weak binding of GtgE to the peptide encompassing the Rab29 cleavage site. In view of the low in vitro activity and poor substrate binding, we postulate that the function of GtgE in vivo as a proteolytic enzyme is dependent on other factor(s), such as a protein partner or interactions with the SCV membrane, which stimulate(s) GtgE activity in vivo. Public Library of Science 2016-12-06 /pmc/articles/PMC5140068/ /pubmed/27923041 http://dx.doi.org/10.1371/journal.pone.0166643 Text en © 2016 Xu et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Xu, Caishuang Kozlov, Guennadi Wong, Kathy Gehring, Kalle Cygler, Miroslaw Crystal Structure of the Salmonella Typhimurium Effector GtgE |
title | Crystal Structure of the Salmonella Typhimurium Effector GtgE |
title_full | Crystal Structure of the Salmonella Typhimurium Effector GtgE |
title_fullStr | Crystal Structure of the Salmonella Typhimurium Effector GtgE |
title_full_unstemmed | Crystal Structure of the Salmonella Typhimurium Effector GtgE |
title_short | Crystal Structure of the Salmonella Typhimurium Effector GtgE |
title_sort | crystal structure of the salmonella typhimurium effector gtge |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5140068/ https://www.ncbi.nlm.nih.gov/pubmed/27923041 http://dx.doi.org/10.1371/journal.pone.0166643 |
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