1l4i
From Proteopedia
(New page: 200px<br /><applet load="1l4i" size="450" color="white" frame="true" align="right" spinBox="true" caption="1l4i, resolution 2.20Å" /> '''Crystal Structure of...) |
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| - | [[Image:1l4i.gif|left|200px]]<br /><applet load="1l4i" size=" | + | [[Image:1l4i.gif|left|200px]]<br /><applet load="1l4i" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1l4i, resolution 2.20Å" /> | caption="1l4i, resolution 2.20Å" /> | ||
'''Crystal Structure of the Periplasmic Chaperone SfaE'''<br /> | '''Crystal Structure of the Periplasmic Chaperone SfaE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | S pili are sialic acid binding hair-like appendages expressed by | + | S pili are sialic acid binding hair-like appendages expressed by pathogenic strains of Escherichia coli. The presence of S pili has been implicated as a virulence factor in both urinary-tract infections and new-born meningitis. Assembly of S pili proceeds via the ubiquitous chaperone/usher pathway. Previously, structures of the homologous chaperones PapD and FimC involved in assembly of P and type-1 pili, respectively, have been solved. Here, the 2.2 A X-ray structure of the S pilus chaperone SfaE is reported. SfaE has the same overall L-shaped structure as PapD and FimC, with two immunoglobulin-like domains oriented at about a 90 degrees angle to each other. Conserved residues in the subunit-binding cleft known to be critical for chaperone function occupy essentially identical positions in SfaE, FimC and PapD. As in free PapD and FimC, the long F1-G1 loop connecting the two last strands of the N-terminal domain is disordered. SfaE crystallizes as a dimer with an extensive dimer interface involving the subunit-binding surfaces of the chaperone. Dimerization via these regions has previously been observed for PapD and might be a general side effect arising from the subunit-binding properties of periplasmic chaperones. The domain interface contains an extended hydrogen-bond network involving three invariant charged residues and two structurally conserved water molecules. It is suggested that disruption of the domain interactions may destabilize the N-terminal domain through exposure of three conserved hydrophobic residues, thereby promoting release of pilus subunits during pilus assembly. |
==About this Structure== | ==About this Structure== | ||
| - | 1L4I 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:// | + | 1L4I 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=1L4I OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Choudhury, D.]] | [[Category: Choudhury, D.]] | ||
[[Category: Hultgren, S.]] | [[Category: Hultgren, S.]] | ||
| - | [[Category: Knight, S | + | [[Category: Knight, S D.]] |
[[Category: Pinkner, J.]] | [[Category: Pinkner, J.]] | ||
[[Category: Stojanoff, V.]] | [[Category: Stojanoff, V.]] | ||
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[[Category: periplasmic chaperone]] | [[Category: periplasmic chaperone]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:41:15 2008'' |
Revision as of 11:41, 21 February 2008
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Crystal Structure of the Periplasmic Chaperone SfaE
Overview
S pili are sialic acid binding hair-like appendages expressed by pathogenic strains of Escherichia coli. The presence of S pili has been implicated as a virulence factor in both urinary-tract infections and new-born meningitis. Assembly of S pili proceeds via the ubiquitous chaperone/usher pathway. Previously, structures of the homologous chaperones PapD and FimC involved in assembly of P and type-1 pili, respectively, have been solved. Here, the 2.2 A X-ray structure of the S pilus chaperone SfaE is reported. SfaE has the same overall L-shaped structure as PapD and FimC, with two immunoglobulin-like domains oriented at about a 90 degrees angle to each other. Conserved residues in the subunit-binding cleft known to be critical for chaperone function occupy essentially identical positions in SfaE, FimC and PapD. As in free PapD and FimC, the long F1-G1 loop connecting the two last strands of the N-terminal domain is disordered. SfaE crystallizes as a dimer with an extensive dimer interface involving the subunit-binding surfaces of the chaperone. Dimerization via these regions has previously been observed for PapD and might be a general side effect arising from the subunit-binding properties of periplasmic chaperones. The domain interface contains an extended hydrogen-bond network involving three invariant charged residues and two structurally conserved water molecules. It is suggested that disruption of the domain interactions may destabilize the N-terminal domain through exposure of three conserved hydrophobic residues, thereby promoting release of pilus subunits during pilus assembly.
About this Structure
1L4I is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure of the S pilus periplasmic chaperone SfaE at 2.2 A resolution., Knight SD, Choudhury D, Hultgren S, Pinkner J, Stojanoff V, Thompson A, Acta Crystallogr D Biol Crystallogr. 2002 Jun;58(Pt 6 Pt 2):1016-22. Epub, 2002 May 29. PMID:12037304
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