2ivz
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The natively disordered N-terminal 83-aa translocation (T) domain of E, group nuclease colicins recruits OmpF to a colicin-receptor complex in the, outer membrane (OM) as well as TolB in the periplasm of Escherichia coli, the latter triggering translocation of the toxin across the OM. We have, identified the 16-residue TolB binding epitope in the natively disordered, T-domain of the nuclease colicin E9 (ColE9) and solved the crystal, structure of the complex. ColE9 folds into a distorted hairpin within a, canyon of the six-bladed beta-propeller of TolB, using two tryptophans to, bolt the toxin to the canyon floor and numerous intramolecular hydrogen, bonds to stabilize the bound conformation. This mode of binding enables, colicin side chains to hydrogen-bond TolB residues in and around ... | + | The natively disordered N-terminal 83-aa translocation (T) domain of E, group nuclease colicins recruits OmpF to a colicin-receptor complex in the, outer membrane (OM) as well as TolB in the periplasm of Escherichia coli, the latter triggering translocation of the toxin across the OM. We have, identified the 16-residue TolB binding epitope in the natively disordered, T-domain of the nuclease colicin E9 (ColE9) and solved the crystal, structure of the complex. ColE9 folds into a distorted hairpin within a, canyon of the six-bladed beta-propeller of TolB, using two tryptophans to, bolt the toxin to the canyon floor and numerous intramolecular hydrogen, bonds to stabilize the bound conformation. This mode of binding enables, colicin side chains to hydrogen-bond TolB residues in and around the, channel that runs through the beta-propeller and that constitutes the, binding site of peptidoglycan-associated lipoprotein (Pal). Pal is a, globular binding partner of TolB, and their association is known to be, important for OM integrity. The structure is therefore consistent with, translocation models wherein the colicin disrupts the TolB-Pal complex, causing local instability of the OM as a prelude to toxin import., Intriguingly, Ca(2+) ions, which bind within the beta-propeller channel, and switch the surface electrostatics from negative to positive, are, needed for the negatively charged T-domain to bind TolB with an affinity, equivalent to that of Pal and competitively displace it. Our study, demonstrates that natively disordered proteins can compete with globular, proteins for binding to folded scaffolds but that this can require, cofactors such as metal ions to offset unfavorable interactions. |
==About this Structure== | ==About this Structure== | ||
| - | 2IVZ is a | + | 2IVZ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2IVZ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transport]] | [[Category: transport]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:47:19 2007'' |
Revision as of 11:42, 5 November 2007
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STRUCTURE OF TOLB IN COMPLEX WITH A PEPTIDE OF THE COLICIN E9 T-DOMAIN
Overview
The natively disordered N-terminal 83-aa translocation (T) domain of E, group nuclease colicins recruits OmpF to a colicin-receptor complex in the, outer membrane (OM) as well as TolB in the periplasm of Escherichia coli, the latter triggering translocation of the toxin across the OM. We have, identified the 16-residue TolB binding epitope in the natively disordered, T-domain of the nuclease colicin E9 (ColE9) and solved the crystal, structure of the complex. ColE9 folds into a distorted hairpin within a, canyon of the six-bladed beta-propeller of TolB, using two tryptophans to, bolt the toxin to the canyon floor and numerous intramolecular hydrogen, bonds to stabilize the bound conformation. This mode of binding enables, colicin side chains to hydrogen-bond TolB residues in and around the, channel that runs through the beta-propeller and that constitutes the, binding site of peptidoglycan-associated lipoprotein (Pal). Pal is a, globular binding partner of TolB, and their association is known to be, important for OM integrity. The structure is therefore consistent with, translocation models wherein the colicin disrupts the TolB-Pal complex, causing local instability of the OM as a prelude to toxin import., Intriguingly, Ca(2+) ions, which bind within the beta-propeller channel, and switch the surface electrostatics from negative to positive, are, needed for the negatively charged T-domain to bind TolB with an affinity, equivalent to that of Pal and competitively displace it. Our study, demonstrates that natively disordered proteins can compete with globular, proteins for binding to folded scaffolds but that this can require, cofactors such as metal ions to offset unfavorable interactions.
About this Structure
2IVZ is a Protein complex structure of sequences from Escherichia coli with CA as ligand. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Competitive recruitment of the periplasmic translocation portal TolB by a natively disordered domain of colicin E9., Loftus SR, Walker D, Mate MJ, Bonsor DA, James R, Moore GR, Kleanthous C, Proc Natl Acad Sci U S A. 2006 Aug 15;103(33):12353-8. Epub 2006 Aug 7. PMID:16894158
Page seeded by OCA on Mon Nov 5 13:47:19 2007
Categories: Escherichia coli | Protein complex | Bonsor, D.A. | James, R. | Kleanthous, C. | Loftus, S.R. | Mate, M.J. | Moore, G.R. | Walker, D. | CA | Antibiotic | Antimicrobial | Bacteriocin | Bacteriocin transport | Colicin | Endonuclease | Hydrolase | Natively disordered proteins | Nuclease | Periplasmic | Plasmid | Protein transport | Protein transport/hydrolase complex | Protein-protein interaction | Tolb | Translocation | Transport
