1ek9: Difference between revisions

Revision as of 13:28, 21 February 2008

2.1A X-RAY STRUCTURE OF TOLC: AN INTEGRAL OUTER MEMBRANE PROTEIN AND EFFLUX PUMP COMPONENT FROM ESCHERICHIA COLI

OverviewOverview

Diverse molecules, from small antibacterial drugs to large protein toxins, are exported directly across both cell membranes of gram-negative bacteria. This export is brought about by the reversible interaction of substrate-specific inner-membrane proteins with an outer-membrane protein of the TolC family, thus bypassing the intervening periplasm. Here we report the 2.1-A crystal structure of TolC from Escherichia coli, revealing a distinctive and previously unknown fold. Three TolC protomers assemble to form a continuous, solvent-accessible conduit--a 'channel-tunnel' over 140 A long that spans both the outer membrane and periplasmic space. The periplasmic or proximal end of the tunnel is sealed by sets of coiled helices. We suggest these could be untwisted by an allosteric mechanism, mediated by protein-protein interactions, to open the tunnel. The structure provides an explanation of how the cell cytosol is connected to the external environment during export, and suggests a general mechanism for the action of bacterial efflux pumps.

About this StructureAbout this Structure

1EK9 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of the bacterial membrane protein TolC central to multidrug efflux and protein export., Koronakis V, Sharff A, Koronakis E, Luisi B, Hughes C, Nature. 2000 Jun 22;405(6789):914-9. PMID:10879525

Page seeded by OCA on Thu Feb 21 12:28:39 2008

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OCA

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-[[Image:1ek9.gif|left|200px]]<br />
+[[Image:1ek9.gif|left|200px]]<br /><applet load="1ek9" size="350" color="white" frame="true" align="right" spinBox="true"
-<applet load="1ek9" size="450" color="white" frame="true" align="right" spinBox="true"
 caption="1ek9, resolution 2.1&Aring;" />
 '''2.1A X-RAY STRUCTURE OF TOLC: AN INTEGRAL OUTER MEMBRANE PROTEIN AND EFFLUX PUMP COMPONENT FROM ESCHERICHIA COLI'''<br />
 ==Overview==
-Diverse molecules, from small antibacterial drugs to large protein toxins, are exported directly across both cell membranes of gram-negative, bacteria. This export is brought about by the reversible interaction of, substrate-specific inner-membrane proteins with an outer-membrane protein, of the TolC family, thus bypassing the intervening periplasm. Here we, report the 2.1-A crystal structure of TolC from Escherichia coli, revealing a distinctive and previously unknown fold. Three TolC protomers, assemble to form a continuous, solvent-accessible conduit--a, 'channel-tunnel' over 140 A long that spans both the outer membrane and, periplasmic space. The periplasmic or proximal end of the tunnel is sealed, by sets of coiled helices. We suggest these could be untwisted by an, allosteric mechanism, mediated by protein-protein interactions, to open, the tunnel. The structure provides an explanation of how the cell cytosol, is connected to the external environment during export, and suggests a, general mechanism for the action of bacterial efflux pumps.
+Diverse molecules, from small antibacterial drugs to large protein toxins, are exported directly across both cell membranes of gram-negative bacteria. This export is brought about by the reversible interaction of substrate-specific inner-membrane proteins with an outer-membrane protein of the TolC family, thus bypassing the intervening periplasm. Here we report the 2.1-A crystal structure of TolC from Escherichia coli, revealing a distinctive and previously unknown fold. Three TolC protomers assemble to form a continuous, solvent-accessible conduit--a 'channel-tunnel' over 140 A long that spans both the outer membrane and periplasmic space. The periplasmic or proximal end of the tunnel is sealed by sets of coiled helices. We suggest these could be untwisted by an allosteric mechanism, mediated by protein-protein interactions, to open the tunnel. The structure provides an explanation of how the cell cytosol is connected to the external environment during export, and suggests a general mechanism for the action of bacterial efflux pumps.
 ==About this Structure==
-EK9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1EK9 OCA].
+EK9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EK9 OCA].
 ==Reference==
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 [[Category: Koronakis, V.]]
 [[Category: Luisi, B.]]
-[[Category: Sharff, A.J.]]
+[[Category: Sharff, A J.]]
 [[Category: alpha helical barrel]]
 [[Category: beta barrel]]
 [[Category: integral membrane protein]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 18 08:59:35 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:28:39 2008''