8H25

Lacticaseibacillus casei GH35 beta-galactosidase LBCZ_0230

Summary for 8H25

• Entry DOI: 10.2210/pdb8h25/pdb
• Descriptor: Beta-galactosidase, DI(HYDROXYETHYL)ETHER, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (5 entities in total)
• Functional Keywords: beta-galactosidase, gh35, lacto-n-biose 1, galacto-n-biose, hydrolase
• Biological source: Lacticaseibacillus casei
• Total number of polymer chains: 4
• Total formula weight: 277078.79

Authors

Saburi, W.,Ota, T.,Kato, K.,Tagami, T.,Yamashita, K.,Yao, M.,Mori, H. (deposition date: 2022-10-04, release date: 2023-08-16, Last modification date: 2024-05-08)

Primary citation

Saburi, W.,Ota, T.,Kato, K.,Tagami, T.,Yamashita, K.,Yao, M.,Mori, H.
Function and Structure of Lacticaseibacillus casei GH35 beta-Galactosidase LBCZ_0230 with High Hydrolytic Activity to Lacto- N -biose I and Galacto- N -biose.
J Appl Glycosci (1999), 70:43-52, 2023

PubMed Abstract: β-Galactosidase (EC 3.2.1.23) hydrolyzes β-D-galactosidic linkages at the non-reducing end of substrates to produce β-D-galactose. is one of the most widely utilized probiotic species of lactobacilli. It possesses a putative β-galactosidase belonging to glycoside hydrolase family 35 (GH35). This enzyme is encoded by the gene included in the gene cluster for utilization of lacto--biose I (LNB; Galβ1-3GlcNAc) and galacto--biose (GNB; Galβ1-3GalNAc) the phosphoenolpyruvate: sugar phosphotransferase system. The GH35 protein (GnbG) from BL23 is predicted to be 6-phospho-β-galactosidase (EC 3.2.1.85). However, its 6-phospho-β-galactosidase activity has not yet been examined, whereas its hydrolytic activity against LNB and GNB has been demonstrated. In this study, JCM1134 LBCZ_0230, homologous to GnbG, was characterized enzymatically and structurally. A recombinant LBCZ_0230, produced in , exhibited high hydrolytic activity toward -nitrophenyl β-D-galactopyranoside, -nitrophenyl β-D-galactopyranoside, LNB, and GNB, but not toward -nitrophenyl 6-phospho-β-D-galactopyranoside. Crystal structure analysis indicates that the structure of subsite -1 of LBCZ_0230 is very similar to that of β-galactosidase BgaC and not suitable for binding to 6-phospho-β-D-galactopyranoside. These biochemical and structural analyses indicate that LBCZ_0230 is a β-galactosidase. According to the prediction of LNB's binding mode, aromatic residues, Trp190, Trp240, Trp243, Phe244, and Tyr458, form hydrophobic interactions with -acetyl-D-glucosamine residue of LNB at subsite +1.

PubMed: 37599861
DOI: 10.5458/jag.jag.JAG-2022_0014

Experimental method

X-RAY DIFFRACTION (2.295 Å)