6KRN

Crystal structure of GH30 xylanase B from Talaromyces cellulolyticus expressed by Pichia pastoris in complex with aldotriuronic acid

Summary for 6KRN

• Entry DOI: 10.2210/pdb6krn/pdb
• Related: 6KRL
• Descriptor: Mating factor alpha,GH30 Xylanase B, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-3)-alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (6 entities in total)
• Functional Keywords: xylanase, glucuronoxylanase, hydrolase
• Biological source: Saccharomyces uvarum (Yeast); More
• Total number of polymer chains: 1
• Total formula weight: 63030.66

Authors

Nakamichi, Y.,Watanabe, M.,Inoue, H. (deposition date: 2019-08-22, release date: 2020-06-17, Last modification date: 2023-11-22)

Primary citation

Nakamichi, Y.,Watanabe, M.,Matsushika, A.,Inoue, H.
Substrate recognition by a bifunctional GH30-7 xylanase B from Talaromyces cellulolyticus.
Febs Open Bio, 10:1180-1189, 2020

PubMed Abstract: Xylanase B, a member of subfamily 7 of the GH30 (glycoside hydrolase family 30) from Talaromyces cellulolyticus (TcXyn30B), is a bifunctional enzyme with glucuronoxylanase and xylobiohydrolase activities. In the present study, crystal structures of the native enzyme and the enzyme-product complex of TcXyn30B expressed in Pichia pastoris were determined at resolutions of 1.60 and 1.65 Å, respectively. The enzyme complexed with 2 -(4-O-methyl-α-d-glucuronyl)-xylobiose (U X) revealed that TcXyn30B strictly recognizes both the C-6 carboxyl group and the 4-O-methyl group of the 4-O-methyl-α-d-glucuronyl side chain by the conserved residues in GH30-7 endoxylanases. The crystal structure and site-directed mutagenesis indicated that Asn-93 on the β2-α2-loop interacts with the non-reducing end of the xylose residue at subsite-2 and is likely to be involved in xylobiohydrolase activity. These findings provide structural insight into the mechanisms of substrate recognition of GH30-7 glucuronoxylanase and xylobiohydrolase.

PubMed: 32359208
DOI: 10.1002/2211-5463.12873

Experimental method

X-RAY DIFFRACTION (1.653 Å)