Cargando…
The dynamic action of SecA during the initiation of protein translocation
The motor ATPase SecA drives protein secretion through the bacterial Sec complex. The PPXD (pre-protein cross-linking domain) of the enzyme has been observed in different positions, effectively opening and closing a clamp for the polypeptide substrate. We set out to explore the implicated dynamic ro...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Portland Press Ltd.
2013
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3685266/ https://www.ncbi.nlm.nih.gov/pubmed/23126322 http://dx.doi.org/10.1042/BJ20121314 |
_version_ | 1782273674136518656 |
---|---|
author | Gold, Vicki A. M. Whitehouse, Sarah Robson, Alice Collinson, Ian |
author_facet | Gold, Vicki A. M. Whitehouse, Sarah Robson, Alice Collinson, Ian |
author_sort | Gold, Vicki A. M. |
collection | PubMed |
description | The motor ATPase SecA drives protein secretion through the bacterial Sec complex. The PPXD (pre-protein cross-linking domain) of the enzyme has been observed in different positions, effectively opening and closing a clamp for the polypeptide substrate. We set out to explore the implicated dynamic role of the PPXD in protein translocation by examining the effects of its immobilization, either in the position occupied in SecA alone with the clamp held open or when in complex with SecYEG with the clamp closed. We show that the conformational change from the former to the latter is necessary for high-affinity association with SecYEG and a corresponding activation of ATPase activity, presumably due to the PPXD contacting the NBDs (nucleotide-binding domains). In either state, the immobilization prevents pre-protein transport. However, when the PPXD was attached to an alternative position in the associated SecYEG complex, with the clamp closed, the transport capability was preserved. Therefore large-scale conformational changes of this domain are required for the initiation process, but not for translocation itself. The results allow us to refine a model for protein translocation, in which the mobility of the PPXD facilitates the transfer of pre-protein from SecA to SecYEG. |
format | Online Article Text |
id | pubmed-3685266 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Portland Press Ltd. |
record_format | MEDLINE/PubMed |
spelling | pubmed-36852662013-06-20 The dynamic action of SecA during the initiation of protein translocation Gold, Vicki A. M. Whitehouse, Sarah Robson, Alice Collinson, Ian Biochem J Research Article The motor ATPase SecA drives protein secretion through the bacterial Sec complex. The PPXD (pre-protein cross-linking domain) of the enzyme has been observed in different positions, effectively opening and closing a clamp for the polypeptide substrate. We set out to explore the implicated dynamic role of the PPXD in protein translocation by examining the effects of its immobilization, either in the position occupied in SecA alone with the clamp held open or when in complex with SecYEG with the clamp closed. We show that the conformational change from the former to the latter is necessary for high-affinity association with SecYEG and a corresponding activation of ATPase activity, presumably due to the PPXD contacting the NBDs (nucleotide-binding domains). In either state, the immobilization prevents pre-protein transport. However, when the PPXD was attached to an alternative position in the associated SecYEG complex, with the clamp closed, the transport capability was preserved. Therefore large-scale conformational changes of this domain are required for the initiation process, but not for translocation itself. The results allow us to refine a model for protein translocation, in which the mobility of the PPXD facilitates the transfer of pre-protein from SecA to SecYEG. Portland Press Ltd. 2013-01-09 2013-02-01 /pmc/articles/PMC3685266/ /pubmed/23126322 http://dx.doi.org/10.1042/BJ20121314 Text en © 2013 The author(s) has paid for this article to be freely available under the terms of the Creative Commons Attribution Licence (CC-BY)(http://creativecommons.org/licenses/by/3.0/) which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Gold, Vicki A. M. Whitehouse, Sarah Robson, Alice Collinson, Ian The dynamic action of SecA during the initiation of protein translocation |
title | The dynamic action of SecA during the initiation of protein translocation |
title_full | The dynamic action of SecA during the initiation of protein translocation |
title_fullStr | The dynamic action of SecA during the initiation of protein translocation |
title_full_unstemmed | The dynamic action of SecA during the initiation of protein translocation |
title_short | The dynamic action of SecA during the initiation of protein translocation |
title_sort | dynamic action of seca during the initiation of protein translocation |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3685266/ https://www.ncbi.nlm.nih.gov/pubmed/23126322 http://dx.doi.org/10.1042/BJ20121314 |
work_keys_str_mv | AT goldvickiam thedynamicactionofsecaduringtheinitiationofproteintranslocation AT whitehousesarah thedynamicactionofsecaduringtheinitiationofproteintranslocation AT robsonalice thedynamicactionofsecaduringtheinitiationofproteintranslocation AT collinsonian thedynamicactionofsecaduringtheinitiationofproteintranslocation AT goldvickiam dynamicactionofsecaduringtheinitiationofproteintranslocation AT whitehousesarah dynamicactionofsecaduringtheinitiationofproteintranslocation AT robsonalice dynamicactionofsecaduringtheinitiationofproteintranslocation AT collinsonian dynamicactionofsecaduringtheinitiationofproteintranslocation |