7CWI

Crystal structure of beta-galactosidase II from Bacillus circulans

7CWI の概要

• エントリーDOI: 10.2210/pdb7cwi/pdb
• 分子名称: beta-galactosidase, GLYCEROL, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: beta-galactosidase, carbohydrate, hydrolase
• 由来する生物種: Bacillus circulans
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 93117.15

構造登録者

Hong, H.,Seo, H. (登録日: 2020-08-28, 公開日: 2020-12-09, 最終更新日: 2023-11-29)

主引用文献

Choi, J.Y.,Hong, H.,Seo, H.,Pan, J.G.,Kim, E.J.,Maeng, P.J.,Yang, T.H.,Kim, K.J.
High Galacto-Oligosaccharide Production and a Structural Model for Transgalactosylation of beta-Galactosidase II from Bacillus circulans .
J.Agric.Food Chem., 68:13806-13814, 2020

PubMed Abstract: The transgalactosylase activity of β-galactosidase produces galacto-oligosaccharides (GOSs) with prebiotic effects similar to those of major oligosaccharides in human milk. β-Galactosidases from ATCC 31382 are important enzymes in industrial-scale GOS production. Here, we show the high GOS yield of β-galactosidase II from (β-Gal-II, Lactazyme-B), compared to other commercial enzymes. We also determine the crystal structure of the five conserved domains of β-Gal-II in an apo-form and complexed with galactose and an acceptor sugar, showing the heterogeneous mode of transgalactosylation by the enzyme. Truncation studies of the five conserved domains reveal that all five domains are essential for enzyme catalysis, while some truncated constructs were still expressed as soluble proteins. Structural comparison of β-Gal-II with other β-galactosidase homologues suggests that the GOS linkage preference of the enzyme might be quite different from other enzymes. The structural information on β-Gal-II might provide molecular insights into the transgalactosylation process of the β-galactosidases in GOS production.

PubMed: 33169609
DOI: 10.1021/acs.jafc.0c05871

実験手法

X-RAY DIFFRACTION (1.95 Å)