1bed
From Proteopedia
(New page: 200px<br /><applet load="1bed" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bed, resolution 2.0Å" /> '''STRUCTURE OF DISULFID...) |
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caption="1bed, resolution 2.0Å" /> | caption="1bed, resolution 2.0Å" /> | ||
'''STRUCTURE OF DISULFIDE OXIDOREDUCTASE'''<br /> | '''STRUCTURE OF DISULFIDE OXIDOREDUCTASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The efficient and correct folding of bacterial disulfide bonded proteins | + | The efficient and correct folding of bacterial disulfide bonded proteins in vivo is dependent upon a class of periplasmic oxidoreductase proteins called DsbA, after the Escherichia coli enzyme. In the pathogenic bacterium Vibrio cholerae, the DsbA homolog (TcpG) is responsible for the folding, maturation and secretion of virulence factors. Mutants in which the tcpg gene has been inactivated are avirulent; they no longer produce functional colonisation pili and they no longer secrete cholera toxin. TcpG is thus a suitable target for inhibitors that could counteract the virulence of this organism, thereby preventing the symptoms of cholera. The crystal structure of oxidized TcpG (refined at a resolution of 2.1 A) serves as a starting point for the rational design of such inhibitors. As expected, TcpG has the same fold as E. coli DsbA, with which it shares approximately 40% sequence identity. In addition, the characteristic surface features of DsbA are present in TcpG, supporting the notion that these features play a functional role. While the overall architecture of TcpG and DsbA is similar and the surface features are retained in TcpG, there are significant differences. For example, the kinked active site helix results from a three-residue loop in DsbA, but is caused by a proline in TcpG (making TcpG more similar to thioredoxin in this respect). Furthermore, the proposed peptide binding groove of TcpG is substantially shortened compared with that of DsbA due to a six-residue deletion. Also, the hydrophobic pocket of TcpG is more shallow and the acidic patch is much less extensive than that of E. coli DsbA. The identification of the structural and surface features that are retained or are divergent in TcpG provides a useful assessment of their functional importance in these protein folding catalysts and is an important prerequisite for the design of TcpG inhibitors. |
==About this Structure== | ==About this Structure== | ||
| - | 1BED is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. Full crystallographic information is available from [http:// | + | 1BED is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BED OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Vibrio cholerae]] | [[Category: Vibrio cholerae]] | ||
| - | [[Category: Hu, S | + | [[Category: Hu, S H.]] |
| - | [[Category: Martin, J | + | [[Category: Martin, J L.]] |
[[Category: disulfide oxidoreductase]] | [[Category: disulfide oxidoreductase]] | ||
[[Category: protein disulfide isomerase]] | [[Category: protein disulfide isomerase]] | ||
[[Category: tcpg]] | [[Category: tcpg]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:54:27 2008'' |
Revision as of 09:54, 21 February 2008
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STRUCTURE OF DISULFIDE OXIDOREDUCTASE
Overview
The efficient and correct folding of bacterial disulfide bonded proteins in vivo is dependent upon a class of periplasmic oxidoreductase proteins called DsbA, after the Escherichia coli enzyme. In the pathogenic bacterium Vibrio cholerae, the DsbA homolog (TcpG) is responsible for the folding, maturation and secretion of virulence factors. Mutants in which the tcpg gene has been inactivated are avirulent; they no longer produce functional colonisation pili and they no longer secrete cholera toxin. TcpG is thus a suitable target for inhibitors that could counteract the virulence of this organism, thereby preventing the symptoms of cholera. The crystal structure of oxidized TcpG (refined at a resolution of 2.1 A) serves as a starting point for the rational design of such inhibitors. As expected, TcpG has the same fold as E. coli DsbA, with which it shares approximately 40% sequence identity. In addition, the characteristic surface features of DsbA are present in TcpG, supporting the notion that these features play a functional role. While the overall architecture of TcpG and DsbA is similar and the surface features are retained in TcpG, there are significant differences. For example, the kinked active site helix results from a three-residue loop in DsbA, but is caused by a proline in TcpG (making TcpG more similar to thioredoxin in this respect). Furthermore, the proposed peptide binding groove of TcpG is substantially shortened compared with that of DsbA due to a six-residue deletion. Also, the hydrophobic pocket of TcpG is more shallow and the acidic patch is much less extensive than that of E. coli DsbA. The identification of the structural and surface features that are retained or are divergent in TcpG provides a useful assessment of their functional importance in these protein folding catalysts and is an important prerequisite for the design of TcpG inhibitors.
About this Structure
1BED is a Single protein structure of sequence from Vibrio cholerae. Full crystallographic information is available from OCA.
Reference
Structure of TcpG, the DsbA protein folding catalyst from Vibrio cholerae., Hu SH, Peek JA, Rattigan E, Taylor RK, Martin JL, J Mol Biol. 1997 Apr 25;268(1):137-46. PMID:9149147
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