Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	The variable structural flexibility of the Bacillus circulans β-galactosidase isoforms determines their unique functionalities.
Journal, issue, pages	Structure, Vol. 32, Issue 11, Page 2023-22037.e5, Year 2024
Publish date	Sep 26, 2024
Authors	Michaela Hovorková / Barbora Kaščáková / Lucie Petrásková / Petra Havlíčková / Jiří Nováček / Daniel Pinkas / Zdenko Gardian / Vladimír Křen / Pavla Bojarová / Ivana Kutá Smatanová /
PubMed Abstract	β-Galactosidase from Bacillus circulans ATCC 31382 (BgaD) is a biotechnologically important enzyme for the synthesis of β-galactooligosaccharides (GOS). Among its four isoforms, isoform A (BgaD-A) ...β-Galactosidase from Bacillus circulans ATCC 31382 (BgaD) is a biotechnologically important enzyme for the synthesis of β-galactooligosaccharides (GOS). Among its four isoforms, isoform A (BgaD-A) has distinct synthetic properties. Here, we present cryoelectron microscopy (cryo-EM) structures of BgaD-A and compare them with the known X-ray crystal structure of isoform D (BgaD-D), revealing substantial structural divergences between the two isoforms. In contrast to BgaD-D, BgaD-A features a flexible Big-4 domain and another enigmatic domain. The newly identified flexible region in BgaD-A is termed as "barrier domain 8," and serves as a barricade, obstructing the access of longer oligosaccharide substrates into the active site of BgaD-A. The transgalactosylation reactions catalyzed by both isoforms revealed that BgaD-A has a higher selectivity than BgaD-D in the earlier stages of the reaction and is prevailingly directed to shorter galactooligosaccharides. This study improves our understanding of the structural determinants governing β-galactosidase catalysis, with implications for tailored GOS production.
External links	Structure / PubMed:39353423
Methods	EM (single particle)
Resolution	3.2 - 4.0 Å
Structure data	18108 8q2h EMDB-18108, PDB-8q2h: beta-galactosidase from Bacillus circulans Method: EM (single particle) / Resolution: 3.2 Å 18153 8q4y EMDB-18153, PDB-8q4y: Beta-galactosidase from Bacillus circulans conformational state 1 Method: EM (single particle) / Resolution: 4.0 Å 18157 8q51 EMDB-18157, PDB-8q51: Beta-galactosidase from Bacillus circulans conformational state 2 Method: EM (single particle) / Resolution: 4.0 Å
Source	niallia circulans subsp. circulans (bacteria) niallia circulans (bacteria)
Keywords	HYDROLASE / Galactosidase / Transgalactosylation / Izoform A / Enzyme