ジャーナル: ACS Chem Biol / 年: 2020 タイトル: The cryo-EM Structure of β-Galactosidase: Quaternary Structure Guides Protein Engineering. 著者: Samuel Míguez Amil / Elena Jiménez-Ortega / Mercedes Ramírez-Escudero / David Talens-Perales / Julia Marín-Navarro / Julio Polaina / Julia Sanz-Aparicio / Rafael Fernandez-Leiro / 要旨: Lactose intolerance is a common digestive disorder that affects a large proportion of the adult human population. The severity of the symptoms is highly variable, depending on the susceptibility to ...Lactose intolerance is a common digestive disorder that affects a large proportion of the adult human population. The severity of the symptoms is highly variable, depending on the susceptibility to the sugar and the amount digested. For that reason, enzymes that can be used for the production of lactose-free milk and milk derivatives have acquired singular biotechnological importance. One such case is β-galactosidase (TmLac). Here, we report the cryo-EM structure of TmLac at 2.0 Å resolution. The protein features a newly solved domain at its C-terminus, characteristic of the genus , which promotes a peculiar octameric arrangement. We have assessed the constraints imposed by the quaternary protein structure on the construction of hybrid versions of this GH2 enzyme. Carbohydrate binding modules (CBM) from the CBM2 and CBM9 families have been added at either the amino or carboxy terminus, and the structural and functional effects of such modifications have been analyzed. The results provide a basis for the rational design of hybrid enzymes that can be efficiently attached to different solid supports.
全体 : Map of beta-Galactosidase from Thermotoga maritima
全体
名称: Map of beta-Galactosidase from Thermotoga maritima
要素
複合体: Map of beta-Galactosidase from Thermotoga maritima
タンパク質・ペプチド: Beta-galactosidase
リガンド: MAGNESIUM ION
リガンド: water
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超分子 #1: Map of beta-Galactosidase from Thermotoga maritima
超分子
名称: Map of beta-Galactosidase from Thermotoga maritima / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1 詳細: Map from Relion3: Refined 3D after postprocessing using the deposited mask and automatic filtering/sharpening. Sharpened by LocScale