2iw0
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The fungal pathogen Colletotrichum lindemuthianum secretes an endo-chitin | + | The fungal pathogen Colletotrichum lindemuthianum secretes an endo-chitin de-N-acetylase (ClCDA) to modify exposed hyphal chitin during penetration and infection of plants. Although a significant amount of biochemical data is available on fungal chitin de-N-acetylases, no structural data exist. Here we describe the 1.8 A crystal structure of a ClCDA product complex and the analysis of the reaction mechanism using Hammett linear free energy relationships, subsite probing, and atomic absorption spectroscopy studies. The structural data in combination with biochemical data reveal that ClCDA consists of a single domain encompassing a mononuclear metalloenzyme which employs a conserved His-His-Asp zinc-binding triad closely associated with the conserved catalytic base (aspartic acid) and acid (histidine) to carry out acid/base catalysis. The data presented here indicate that ClCDA possesses a highly conserved substrate-binding groove, with subtle alterations that influence substrate specificity and subsite affinity. Strikingly, the structure also shows that the hexahistidine purification tag appears to form a tight interaction with the active site groove. The enzyme requires occupancy of at least the 0 and +1 subsites by (GlcNAc)(2) for activity and proceeds through a tetrahedral oxyanion intermediate. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Glomerella lindemuthiana]] | [[Category: Glomerella lindemuthiana]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Aalten, D | + | [[Category: Aalten, D M.F Van.]] |
| - | [[Category: Blair, D | + | [[Category: Blair, D E.]] |
[[Category: Hekmat, O.]] | [[Category: Hekmat, O.]] | ||
| - | [[Category: Schuttelkopf, A | + | [[Category: Schuttelkopf, A W.]] |
[[Category: Shrestha, B.]] | [[Category: Shrestha, B.]] | ||
[[Category: Tokuyasu, K.]] | [[Category: Tokuyasu, K.]] | ||
| - | [[Category: Withers, S | + | [[Category: Withers, S G.]] |
[[Category: ACT]] | [[Category: ACT]] | ||
[[Category: CL]] | [[Category: CL]] | ||
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[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''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 17:56:32 2008'' |
Revision as of 15:56, 21 February 2008
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STRUCTURE OF THE CHITIN DEACETYLASE FROM THE FUNGAL PATHOGEN COLLETOTRICHUM LINDEMUTHIANUM
Overview
The fungal pathogen Colletotrichum lindemuthianum secretes an endo-chitin de-N-acetylase (ClCDA) to modify exposed hyphal chitin during penetration and infection of plants. Although a significant amount of biochemical data is available on fungal chitin de-N-acetylases, no structural data exist. Here we describe the 1.8 A crystal structure of a ClCDA product complex and the analysis of the reaction mechanism using Hammett linear free energy relationships, subsite probing, and atomic absorption spectroscopy studies. The structural data in combination with biochemical data reveal that ClCDA consists of a single domain encompassing a mononuclear metalloenzyme which employs a conserved His-His-Asp zinc-binding triad closely associated with the conserved catalytic base (aspartic acid) and acid (histidine) to carry out acid/base catalysis. The data presented here indicate that ClCDA possesses a highly conserved substrate-binding groove, with subtle alterations that influence substrate specificity and subsite affinity. Strikingly, the structure also shows that the hexahistidine purification tag appears to form a tight interaction with the active site groove. The enzyme requires occupancy of at least the 0 and +1 subsites by (GlcNAc)(2) for activity and proceeds through a tetrahedral oxyanion intermediate.
About this Structure
2IW0 is a Single protein structure of sequence from Glomerella lindemuthiana with , , and as ligands. Active as Chitin deacetylase, with EC number 3.5.1.41 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structure and mechanism of chitin deacetylase from the fungal pathogen Colletotrichum lindemuthianum., Blair DE, Hekmat O, Schuttelkopf AW, Shrestha B, Tokuyasu K, Withers SG, van Aalten DM, Biochemistry. 2006 Aug 8;45(31):9416-26. PMID:16878976
Page seeded by OCA on Thu Feb 21 17:56:32 2008
