7F3A

Arabidopsis thaliana GH1 beta-glucosidase AtBGlu42

Summary for 7F3A

• Entry DOI: 10.2210/pdb7f3a/pdb
• Descriptor: Beta-glucosidase 42, GLYCEROL (3 entities in total)
• Functional Keywords: glycoside hydrolase family 1, beta-glucosidase, hydrolase
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 1
• Total formula weight: 56599.08

Authors

Horikoshi, S.,Saburi, W.,Yu, J.,Yao, M. (deposition date: 2021-06-16, release date: 2022-03-16, Last modification date: 2023-11-29)

Primary citation

Horikoshi, S.,Saburi, W.,Yu, J.,Matsuura, H.,Cairns, J.R.K.,Yao, M.,Mori, H.
Substrate specificity of glycoside hydrolase family 1 beta-glucosidase AtBGlu42 from Arabidopsis thaliana and its molecular mechanism.
Biosci.Biotechnol.Biochem., 86:231-245, 2022

PubMed Abstract: Plants possess many glycoside hydrolase family 1 (GH1) β-glucosidases, which physiologically function in cell wall metabolism and activation of bioactive substances, but most remain uncharacterized. One GH1 isoenzyme AtBGlu42 in Arabidopsis thaliana has been identified to hydrolyze scopolin using the gene deficient plants, but no enzymatic properties were obtained. Its sequence similarity to another functionally characterized enzyme Os1BGlu4 in rice suggests that AtBGlu42 also acts on oligosaccharides. Here, we show that the recombinant AtBGlu42 possesses high kcat/Km not only on scopolin, but also on various β-glucosides, cellooligosaccharides, and laminarioligosaccharides. Of the cellooligosaccharides, cellotriose was the most preferred. The crystal structure, determined at 1.7 Å resolution, suggests that Arg342 gives unfavorable binding to cellooligosaccharides at subsite +3. The mutants R342Y and R342A showed the highest preference on cellotetraose or cellopentaose with increased affinities at subsite +3, indicating that the residues at this position have an important role for chain length specificity.

PubMed: 34965581
DOI: 10.1093/bbb/zbab200

Experimental method

X-RAY DIFFRACTION (1.7 Å)