1YQ2

beta-galactosidase from Arthrobacter sp. C2-2 (isoenzyme C2-2-1)

1YQ2 の概要

• エントリーDOI: 10.2210/pdb1yq2/pdb
• 分子名称: beta-galactosidase, MAGNESIUM ION, SODIUM ION, ... (7 entities in total)
• 機能のキーワード: glycosyl hydrolase family 2; tim barrel; hexamer, hydrolase
• 由来する生物種: Arthrobacter sp. C2-2
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 669203.28

構造登録者

Skalova, T.,Dohnalek, J.,Spiwok, V.,Lipovova, P.,Vondrackova, E.,Petrokova, H.,Strnad, H.,Kralova, B.,Hasek, J. (登録日: 2005-02-01, 公開日: 2005-10-04, 最終更新日: 2023-08-23)

主引用文献

Skalova, T.,Dohnalek, J.,Spiwok, V.,Lipovova, P.,Vondrackova, E.,Petrokova, H.,Duskova, J.,Strnad, H.,Kralova, B.,Hasek, J.
Cold-active beta-Galactosidase from Arthrobacter sp. C2-2 Forms Compact 660kDa Hexamers: Crystal Structure at 1.9A Resolution
J.Mol.Biol., 353:282-294, 2005

PubMed Abstract: The X-ray structure of cold-active beta-galactosidase (isoenzyme C-2-2-1) from an Antarctic bacterium Arthrobacter sp. C2-2 was solved at 1.9A resolution. The enzyme forms 660 kDa hexamers with active sites opened to the central cavity of the hexamer and connected by eight channels with exterior solvent. To our best knowledge, this is the first cold-active beta-galactosidase with known structure and also the first known beta-galactosidase structure in the form of compact hexamers. The hexamer organization regulates access of substrates and ligands to six active sites and this unique packing, present also in solution, raises questions about its purpose and function. This enzyme belongs to glycosyl hydrolase family 2, similarly to Escherichia coli beta-galactosidase, forming tetramers necessary for its enzymatic function. However, we discovered significant differences between these two enzymes affecting the ability of tetramer/hexamer formation and complementation of the active site. This structure reveals new insights into the cold-adaptation mechanisms of enzymatic pathways of extremophiles.

PubMed: 16171818
DOI: 10.1016/j.jmb.2005.08.028

実験手法

X-RAY DIFFRACTION (1.9 Å)