5XC8

Crystal structure of GH45 endoglucanase EG27II at pH5.5, in complex with cellobiose

Summary for 5XC8

• Entry DOI: 10.2210/pdb5xc8/pdb
• Related: 5XBU 5XBX 5XC4 5XCA 5XCB
• Related PRD ID: PRD_900005
• Descriptor: Endo-beta-1,4-glucanase, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: cellulase, glycoside hydrolase family 45, hydrolase
• Biological source: Ampullaria crossean
• Total number of polymer chains: 1
• Total formula weight: 21599.65

Authors

Nomura, T.,Mizutani, K.,Iwase, H.,Takahashi, N.,Mikami, B. (deposition date: 2017-03-22, release date: 2018-03-28, Last modification date: 2023-11-22)

Primary citation

Nomura, T.,Iwase, H.,Saka, N.,Takahashi, N.,Mikami, B.,Mizutani, K.
High-resolution crystal structures of the glycoside hydrolase family 45 endoglucanase EG27II from the snail Ampullaria crossean.
Acta Crystallogr D Struct Biol, 75:426-436, 2019

PubMed Abstract: Although endogenous animal cellulases have great potential for industrial applications such as bioethanol production, few investigations have focused on these enzymes. In this study, the glycoside hydrolase family 45 (GH45) subfamily B endoglucanase EG27II from the snail Ampullaria crossean was expressed using a Pichia pastoris expression system and the crystal structure of the apo form was determined at 1.00 Å resolution; this is the highest resolution structure of an animal endoglucanase. The results showed that EG27II has a double-ψ six-stranded β-barrel and that the structure of EG27II more closely resembles those of subfamily C enzymes than those of subfamily A enzymes. The structure of EG27II complexed with cellobiose was also determined under cryoconditions and at room temperature at three pH values, pH 4.0, 5.5 and 8.0, and no structural changes were found to be associated with the change in pH. The structural comparison and catalytic activity measurements showed that Asp137 and Asn112 function as the catalytic acid and base, respectively, and that Asp27 is also an important residue for catalysis. These high-resolution structures of EG27II provide a large amount of information for structure-based enzyme modification and cell-surface engineering, which will advance biofuel production using animal-derived cellulases.

PubMed: 30988259
DOI: 10.1107/S2059798319003000

Experimental method

X-RAY DIFFRACTION (1.45 Å)