2dqa

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Revision as of 11:24, 23 January 2008

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spinqualitylabelsall models 2dqa, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

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 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.

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 accompany with quaternary structural change., Goto T, Abe Y, Kakuta Y, Takeshita K, Imoto T, Ueda T, J Biol Chem. 2007 Jul 13;. PMID:17631496

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