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Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways
The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier. Escherichia coli periplasmic Zn-metallopeptidase BepA contributes to the maintenance of OM integrity through its involvement in the biogenesis and degradation of LptD, a β-barrel protein component of the...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8423444/ https://www.ncbi.nlm.nih.gov/pubmed/34463613 http://dx.doi.org/10.7554/eLife.70541 |
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author | Miyazaki, Ryoji Watanabe, Tetsuro Yoshitani, Kohei Akiyama, Yoshinori |
author_facet | Miyazaki, Ryoji Watanabe, Tetsuro Yoshitani, Kohei Akiyama, Yoshinori |
author_sort | Miyazaki, Ryoji |
collection | PubMed |
description | The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier. Escherichia coli periplasmic Zn-metallopeptidase BepA contributes to the maintenance of OM integrity through its involvement in the biogenesis and degradation of LptD, a β-barrel protein component of the lipopolysaccharide translocon. BepA either promotes the maturation of LptD when it is on the normal assembly pathway (on-pathway) or degrades it when its assembly is compromised (off-pathway). BepA performs these functions probably on the β‐barrel assembly machinery (BAM) complex. However, how BepA recognizes and directs an immature LptD to different pathways remains unclear. Here, we explored the interactions among BepA, LptD, and the BAM complex. We found that the interaction of the BepA edge-strand located adjacent to the active site with LptD was crucial not only for proteolysis but also, unexpectedly, for assembly promotion of LptD. Site-directed crosslinking analyses indicated that the unstructured N-terminal half of the β-barrel-forming domain of an immature LptD contacts with the BepA edge-strand. Furthermore, the C-terminal region of the β-barrel-forming domain of the BepA-bound LptD intermediate interacted with a ‘seam’ strand of BamA, suggesting that BepA recognized LptD assembling on the BAM complex. Our findings provide important insights into the functional mechanism of BepA. |
format | Online Article Text |
id | pubmed-8423444 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-84234442021-09-09 Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways Miyazaki, Ryoji Watanabe, Tetsuro Yoshitani, Kohei Akiyama, Yoshinori eLife Biochemistry and Chemical Biology The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier. Escherichia coli periplasmic Zn-metallopeptidase BepA contributes to the maintenance of OM integrity through its involvement in the biogenesis and degradation of LptD, a β-barrel protein component of the lipopolysaccharide translocon. BepA either promotes the maturation of LptD when it is on the normal assembly pathway (on-pathway) or degrades it when its assembly is compromised (off-pathway). BepA performs these functions probably on the β‐barrel assembly machinery (BAM) complex. However, how BepA recognizes and directs an immature LptD to different pathways remains unclear. Here, we explored the interactions among BepA, LptD, and the BAM complex. We found that the interaction of the BepA edge-strand located adjacent to the active site with LptD was crucial not only for proteolysis but also, unexpectedly, for assembly promotion of LptD. Site-directed crosslinking analyses indicated that the unstructured N-terminal half of the β-barrel-forming domain of an immature LptD contacts with the BepA edge-strand. Furthermore, the C-terminal region of the β-barrel-forming domain of the BepA-bound LptD intermediate interacted with a ‘seam’ strand of BamA, suggesting that BepA recognized LptD assembling on the BAM complex. Our findings provide important insights into the functional mechanism of BepA. eLife Sciences Publications, Ltd 2021-08-31 /pmc/articles/PMC8423444/ /pubmed/34463613 http://dx.doi.org/10.7554/eLife.70541 Text en © 2021, Miyazaki et al https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Biochemistry and Chemical Biology Miyazaki, Ryoji Watanabe, Tetsuro Yoshitani, Kohei Akiyama, Yoshinori Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways |
title | Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways |
title_full | Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways |
title_fullStr | Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways |
title_full_unstemmed | Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways |
title_short | Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways |
title_sort | edge-strand of bepa interacts with immature lptd on the β-barrel assembly machine to direct it to on- and off-pathways |
topic | Biochemistry and Chemical Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8423444/ https://www.ncbi.nlm.nih.gov/pubmed/34463613 http://dx.doi.org/10.7554/eLife.70541 |
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