4HU8

Crystal Structure of a Bacterial Ig-like Domain Containing GH10 Xylanase from Termite Gut

Summary for 4HU8

• Entry DOI: 10.2210/pdb4hu8/pdb
• Descriptor: GH10 Xylanase, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: (alpha/beta)8 barrel, big2, hydrolase, glycoside hydrolase, bacterial ig-like domain
• Biological source: Globitermes brachycerastes
• Total number of polymer chains: 8
• Total formula weight: 411827.45

Authors

Han, Q.,Liu, N.,Robinson, H.,Cao, L.,Qian, C.,Wang, Q.,Xie, L.,Ding, H.,Wang, Q.,Huang, Y.,Li, J.,Zhou, Z. (deposition date: 2012-11-02, release date: 2013-09-18, Last modification date: 2023-09-20)

Primary citation

Han, Q.,Liu, N.,Robinson, H.,Cao, L.,Qian, C.,Wang, Q.,Xie, L.,Ding, H.,Wang, Q.,Huang, Y.,Li, J.,Zhou, Z.
Biochemical characterization and crystal structure of a GH10 xylanase from termite gut bacteria reveal a novel structural feature and significance of its bacterial Ig-like domain.
Biotechnol.Bioeng., 110:3093-3103, 2013

PubMed Abstract: Bacterial Ig-like (Big) domains are commonly distributed in glycoside hydrolases (GH), but their structure and function remains undefined. Xylanase is a GH, and catalyzes the hydrolysis of the internal β-xylosidic linkages of xylan. In this study, we report the molecular cloning, biochemical and biophysical characterization, and crystal structure of a termite gut bacterial xylanase, Xyl-ORF19, which was derived from gut bacteria of a wood-feeding termite (Globitermes brachycerastes). The protein architecture of Xyl-ORF19 reveals that it has two domains, a C-terminal GH10 catalytic domain and an N-terminal Big_2 non-catalytic domain. The catalytic domain folds in an (α/β)8 barrel as most GH10 xylanases do, but it has two extra β-strands. The non-catalytic domain is structurally similar to an immunoglobulin-like domain of intimins. The recombinant enzyme without the non-catalytic domain has fairly low catalytic activity, and is different from the full-length enzyme in kinetic parameters, pH and temperature profiles, which suggests the non-catalytic domain could affect the enzyme biochemical and biophysical properties as well as the role for enzyme localization. This study provides a molecular basis for future efforts in xylanase bioengineering.

PubMed: 23794438
DOI: 10.1002/bit.24982

Experimental method

X-RAY DIFFRACTION (2 Å)