6M5Z

Catalytic domain of GH30 xylanase C from Talaromyces cellulolyticus

Summary for 6M5Z

• Entry DOI: 10.2210/pdb6m5z/pdb
• Descriptor: GH30 Xylanase C, alpha-D-mannopyranose, GLYCEROL, ... (5 entities in total)
• Functional Keywords: xylanase, hydrolase
• Biological source: Talaromyces cellulolyticus CF-2612
• Total number of polymer chains: 2
• Total formula weight: 96697.08

Authors

Nakamichi, Y.,Watanabe, M.,Inoue, H. (deposition date: 2020-03-12, release date: 2021-01-20, Last modification date: 2024-11-06)

Primary citation

Nakamichi, Y.,Fujii, T.,Watanabe, M.,Matsushika, A.,Inoue, H.
Crystal structure of GH30-7 endoxylanase C from the filamentous fungus Talaromyces cellulolyticus.
Acta Crystallogr.,Sect.F, 76:341-349, 2020

PubMed Abstract: GH30-7 endoxylanase C from the cellulolytic fungus Talaromyces cellulolyticus (TcXyn30C) belongs to glycoside hydrolase family 30 subfamily 7, and specifically releases 2-(4-O-methyl-α-D-glucuronosyl)-xylobiose from glucuronoxylan, as well as various arabino-xylooligosaccharides from arabinoxylan. TcXyn30C has a modular structure consisting of a catalytic domain and a C-terminal cellulose-binding module 1 (CBM1). In this study, the crystal structure of a TcXyn30C mutant which lacks the CBM1 domain was determined at 1.65 Å resolution. The structure of the active site of TcXyn30C was compared with that of the bifunctional GH30-7 xylanase B from T. cellulolyticus (TcXyn30B), which exhibits glucuronoxylanase and xylobiohydrolase activities. The results revealed that TcXyn30C has a conserved structural feature for recognizing the 4-O-methyl-α-D-glucuronic acid (MeGlcA) substituent in subsite -2b. Additionally, the results demonstrated that Phe47 contributes significantly to catalysis by TcXyn30C. Phe47 is located in subsite -2b and also near the C-3 hydroxyl group of a xylose residue in subsite -2a. Substitution of Phe47 with an arginine residue caused a remarkable decrease in the catalytic efficiency towards arabinoxylan, suggesting the importance of Phe47 in arabinoxylan hydrolysis. These findings indicate that subsite -2b of TcXyn30C has unique structural features that interact with arabinofuranose and MeGlcA substituents.

PubMed: 32744245
DOI: 10.1107/S2053230X20009024

Experimental method

X-RAY DIFFRACTION (1.65 Å)