2dqa

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(New page: 200px<br /><applet load="2dqa" size="350" color="white" frame="true" align="right" spinBox="true" caption="2dqa, resolution 1.60&Aring;" /> '''Crystal Structure of...)
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==Overview==
==Overview==
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Tapes Japonica lysozyme (TJL) is classified as a member of the recently, established i-type lysozyme family. In the present study, we solved the, crystal structure of TJL complexed with a trimer of N-acetylglucosamine to, 1.6 A resolution. Based on structure and mutation analyses, we, demonstrated that Glu 18 and Asp 30 are the catalytic residues of TJL., Furthermore, the present findings suggest that the catalytic mechanism of, TJL is a retaining mechanism that proceeds through a covalent sugar-enzyme, intermediate. On the other hand, the quaternary structure in the crystal, revealed a dimer formed by the electrostatic interactions of catalytic, residues (Glu 18 and Asp 30) in one molecule with the positive residues at, the C-terminal in helix 6 of the other molecule. Gel-chromatography, analysis revealed that the TJL dimer remained intact under low-salt, conditions, but that it dissociated to TJL monomers under high-salt, conditions. With increasing salt concentrations, the chitinase activity of, TJL dramatically increased. Therefore, the present study provides novel, evidence that the lysozyme activity of TJL is modulated by its quaternary, structure.
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Tapes japonica lysozyme (TJL) is classified as a member of the recently established i-type lysozyme family. In this study, we solved the crystal structure of TJL complexed with a trimer of N-acetylglucosamine to 1.6A resolution. Based on structure and mutation analyses, we demonstrated that Glu-18 and Asp-30 are the catalytic residues of TJL. Furthermore, the present findings suggest that the catalytic mechanism of TJL is a retaining mechanism that proceeds through a covalent sugar-enzyme intermediate. On the other hand, the quaternary structure in the crystal revealed a dimer formed by the electrostatic interactions of catalytic residues (Glu-18 and Asp-30) in one molecule with the positive residues at the C terminus in helix 6 of the other molecule. Gel chromatography analysis revealed that the TJL dimer remained intact under low salt conditions but that it dissociated to TJL monomers under high salt conditions. With increasing salt concentrations, the chitinase activity of TJL dramatically increased. Therefore, this study provides novel evidence that the lysozyme activity of TJL is modulated by its quaternary structure.
==About this Structure==
==About this Structure==
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==Reference==
==Reference==
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Crystal structure of Tapes japonica lysozyme with substrate analogue ; Structural basis of the catalytic mechanism and manifestation of its chitinase activity accompany with quaternary structural change., Goto T, Abe Y, Kakuta Y, Takeshita K, Imoto T, Ueda T, J Biol Chem. 2007 Jul 13;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17631496 17631496]
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Crystal structure of Tapes japonica Lysozyme with substrate analogue: structural basis of the catalytic mechanism and manifestation of its chitinase activity accompanied by quaternary structural change., Goto T, Abe Y, Kakuta Y, Takeshita K, Imoto T, Ueda T, J Biol Chem. 2007 Sep 14;282(37):27459-67. Epub 2007 Jul 13. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17631496 17631496]
[[Category: Lysozyme]]
[[Category: Lysozyme]]
[[Category: Single protein]]
[[Category: Single protein]]
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[[Category: substrate complex]]
[[Category: substrate complex]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 13:24:19 2008''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:01:31 2008''

Revision as of 15:01, 21 February 2008

Image:2dqa.jpg

2dqa, resolution 1.60Å

Drag the structure with the mouse to rotate

Crystal Structure of Tapes japonica Lysozyme

Overview

Tapes japonica lysozyme (TJL) is classified as a member of the recently established i-type lysozyme family. In this study, we solved the crystal structure of TJL complexed with a trimer of N-acetylglucosamine to 1.6A resolution. Based on structure and mutation analyses, we demonstrated that Glu-18 and Asp-30 are the catalytic residues of TJL. Furthermore, the present findings suggest that the catalytic mechanism of TJL is a retaining mechanism that proceeds through a covalent sugar-enzyme intermediate. On the other hand, the quaternary structure in the crystal revealed a dimer formed by the electrostatic interactions of catalytic residues (Glu-18 and Asp-30) in one molecule with the positive residues at the C terminus in helix 6 of the other molecule. Gel chromatography analysis revealed that the TJL dimer remained intact under low salt conditions but that it dissociated to TJL monomers under high salt conditions. With increasing salt concentrations, the chitinase activity of TJL dramatically increased. Therefore, this study provides novel evidence that the lysozyme activity of TJL is modulated by its quaternary structure.

About this Structure

2DQA is a Single protein structure of sequence from Tapes japonica with and as ligands. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.

Reference

Crystal structure of Tapes japonica Lysozyme with substrate analogue: structural basis of the catalytic mechanism and manifestation of its chitinase activity accompanied by quaternary structural change., Goto T, Abe Y, Kakuta Y, Takeshita K, Imoto T, Ueda T, J Biol Chem. 2007 Sep 14;282(37):27459-67. Epub 2007 Jul 13. PMID:17631496

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