Both ATP and the electrochemical potential are required for optimal assembly of pro-OmpA into Escherichia coli inner membrane vesicles.
AUTOR(ES)
Geller, B L
RESUMO
Pro-OmpA is processed to OmpA by isolated inverted plasma membrane vesicles from Escherichia coli. In the presence of ATP and a membrane potential, 58% (+/- 13%) of the OmpA is sequestered in the vesicles. We sought to determine which of these two metabolic energy sources is used for protein translocation. The plasma membrane F1F0-ATPase is the central enzyme that interconverts the energy of membrane electrochemical potential and ATP. To separate the effects of these two forms of energy in vitro, the ATPase was inactivated, either by "stripping" the F1 from the membranes with low salt and EDTA or by using membrane vesicles derived from a strain without the atp operon. In each case, optimal translocation and processing of pro-OmpA required both a membrane potential and ATP. We conclude that ATP and membrane potential are separate requirements for bacterial protein export.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=323703Documentos Relacionados
- Trigger factor: a soluble protein that folds pro-OmpA into a membrane-assembly-competent form.
- Energy-requiring translocation of the OmpA protein and alkaline phosphatase of Escherichia coli into inner membrane vesicles.
- ATP is essential for protein translocation into Escherichia coli membrane vesicles.
- Effects of nucleotides on ATP-dependent protein translocation into Escherichia coli membrane vesicles.
- ProOmpA spontaneously folds in a membrane assembly competent state which trigger factor stabilizes.