2jow
From Proteopedia
(New page: 200px<br /><applet load="2jow" size="350" color="white" frame="true" align="right" spinBox="true" caption="2jow" /> '''Differences in the electrostatic surfaces of...) |
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==Overview== | ==Overview== | ||
| - | Gram-negative bacteria use a needle-like protein assembly, the type III | + | Gram-negative bacteria use a needle-like protein assembly, the type III secretion apparatus, to inject virulence factors into target cells to initiate human disease. The needle is formed by the polymerization of approximately 120 copies of a small acidic protein that is conserved among diverse pathogens. We previously reported the structure of the BsaL needle monomer from Burkholderia pseudomallei by nuclear magnetic resonance (NMR) spectroscopy and others have determined the crystal structure of the Shigella flexneri MxiH needle. Here, we report the NMR structure of the PrgI needle protein of Salmonella typhimurium, a human pathogen associated with food poisoning. PrgI, BsaL, and MxiH form similar two helix bundles, however, the electrostatic surfaces of PrgI differ radically from those of BsaL or MxiH. In BsaL and MxiH, a large negative area is on a face formed by the helix alpha1-alpha2 interface. In PrgI, the major negatively charged surface is not on the "face" but instead is on the "side" of the two-helix bundle, and only residues from helix alpha1 contribute to this negative region. Despite being highly acidic proteins, these molecules contain large basic regions, suggesting that electrostatic contacts are important in needle assembly. Our results also suggest that needle-packing interactions may be different among these bacteria and provide the structural basis for why PrgI and MxiH, despite 63% sequence identity, are not interchangeable in S. typhimurium and S. flexneri. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Differences in the | + | Differences in the electrostatic surfaces of the type III secretion needle proteins PrgI, BsaL, and MxiH., Wang Y, Ouellette AN, Egan CW, Rathinavelan T, Im W, De Guzman RN, J Mol Biol. 2007 Aug 31;371(5):1304-14. Epub 2007 Jun 15. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17617421 17617421] |
[[Category: Salmonella typhimurium]] | [[Category: Salmonella typhimurium]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Egan, C | + | [[Category: Egan, C W.]] |
| - | [[Category: Guzman, R | + | [[Category: Guzman, R N.De.]] |
| - | [[Category: Ouellette, A | + | [[Category: Ouellette, A N.]] |
[[Category: Wang, Y.]] | [[Category: Wang, Y.]] | ||
[[Category: needle protein]] | [[Category: needle protein]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:04:45 2008'' |
Revision as of 16:04, 21 February 2008
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Differences in the electrostatic surfaces of the type III secretion needle proteins
Overview
Gram-negative bacteria use a needle-like protein assembly, the type III secretion apparatus, to inject virulence factors into target cells to initiate human disease. The needle is formed by the polymerization of approximately 120 copies of a small acidic protein that is conserved among diverse pathogens. We previously reported the structure of the BsaL needle monomer from Burkholderia pseudomallei by nuclear magnetic resonance (NMR) spectroscopy and others have determined the crystal structure of the Shigella flexneri MxiH needle. Here, we report the NMR structure of the PrgI needle protein of Salmonella typhimurium, a human pathogen associated with food poisoning. PrgI, BsaL, and MxiH form similar two helix bundles, however, the electrostatic surfaces of PrgI differ radically from those of BsaL or MxiH. In BsaL and MxiH, a large negative area is on a face formed by the helix alpha1-alpha2 interface. In PrgI, the major negatively charged surface is not on the "face" but instead is on the "side" of the two-helix bundle, and only residues from helix alpha1 contribute to this negative region. Despite being highly acidic proteins, these molecules contain large basic regions, suggesting that electrostatic contacts are important in needle assembly. Our results also suggest that needle-packing interactions may be different among these bacteria and provide the structural basis for why PrgI and MxiH, despite 63% sequence identity, are not interchangeable in S. typhimurium and S. flexneri.
About this Structure
2JOW is a Single protein structure of sequence from Salmonella typhimurium. Full crystallographic information is available from OCA.
Reference
Differences in the electrostatic surfaces of the type III secretion needle proteins PrgI, BsaL, and MxiH., Wang Y, Ouellette AN, Egan CW, Rathinavelan T, Im W, De Guzman RN, J Mol Biol. 2007 Aug 31;371(5):1304-14. Epub 2007 Jun 15. PMID:17617421
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