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Type 1 protein secretion in bacteria, the ABC-transporter dependent pathway (review).
- Source :
-
Molecular membrane biology [Mol Membr Biol] 2005 Jan-Apr; Vol. 22 (1-2), pp. 29-39. - Publication Year :
- 2005
-
Abstract
- The relatively simple type 1 secretion system in gram-negative bacteria is nevertheless capable of transporting polypeptides of up to 800 kDa across the cell envelope in a few seconds. The translocator is composed of an ABC-transporter, providing energy through ATP hydrolysis (and perhaps the initial channel across the inner membrane), linked to a multimeric Membrane Fusion Protein (MFP) spanning the initial part of the periplasm and forming a continuous channel to the surface with an outer membrane trimeric protein. Proteins targeted to the translocator carry an (uncleaved), poorly conserved secretion signal of approximately 50 residues. In E. coli the HlyA toxin interacts with both the MFP (HlyD) and the ABC protein HlyB, (a half transporter) triggering, via a conformational change in HlyD, recruitment of the third component, TolC, into the transenvelope complex. In vitro, HlyA, through its secretion signal, binds to the nucleotide binding domain (NBD or ABC-ATPase) of HlyB in a reaction reversible by ATP that may mimic initial movement of HlyA into the translocation channel. HlyA is then transported rapidly, apparently in an unfolded form, to the cell surface, where folding and release takes place. Whilst recent structural studies of TolC and MFP-like proteins are providing atomic detail of much of the transport path, structural analysis of the HlyB NBD and other ABC ATPases, have revealed details of the catalytic cycle within an NBD dimer and a glimpse of how the action of HlyB is coupled to the translocation of HlyA.
- Subjects :
- Bacterial Proteins chemistry
Bacterial Proteins physiology
Escherichia coli Proteins metabolism
Hemolysin Proteins metabolism
Protein Conformation
Protein Folding
Protein Transport
ATP-Binding Cassette Transporters chemistry
ATP-Binding Cassette Transporters physiology
Bacterial Proteins metabolism
Gram-Negative Bacteria metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0968-7688
- Volume :
- 22
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- Molecular membrane biology
- Publication Type :
- Academic Journal
- Accession number :
- 16092522
- Full Text :
- https://doi.org/10.1080/09687860500042013