6O18

Unliganded alpha-L-fucosidase AlfC from Lactobacillus casei

6O18 の概要

• エントリーDOI: 10.2210/pdb6o18/pdb
• 分子名称: AlfC (2 entities in total)
• 機能のキーワード: fucosidase, apo, hydrolase
• 由来する生物種: Lactobacillus casei
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 157479.00

構造登録者

Klontz, E.H.,Sundberg, E.J. (登録日: 2019-02-18, 公開日: 2020-02-19, 最終更新日: 2023-10-11)

主引用文献

Klontz, E.H.,Li, C.,Kihn, K.,Fields, J.K.,Beckett, D.,Snyder, G.A.,Wintrode, P.L.,Deredge, D.,Wang, L.X.,Sundberg, E.J.
Structure and dynamics of an alpha-fucosidase reveal a mechanism for highly efficient IgG transfucosylation.
Nat Commun, 11:6204-6204, 2020

PubMed Abstract: Fucosylation is important for the function of many proteins with biotechnical and medical applications. Alpha-fucosidases comprise a large enzyme family that recognizes fucosylated substrates with diverse α-linkages on these proteins. Lactobacillus casei produces an α-fucosidase, called AlfC, with specificity towards α(1,6)-fucose, the only linkage found in human N-glycan core fucosylation. AlfC and certain point mutants thereof have been used to add and remove fucose from monoclonal antibody N-glycans, with significant impacts on their effector functions. Despite the potential uses for AlfC, little is known about its mechanism. Here, we present crystal structures of AlfC, combined with mutational and kinetic analyses, hydrogen-deuterium exchange mass spectrometry, molecular dynamic simulations, and transfucosylation experiments to define the molecular mechanisms of the activities of AlfC and its transfucosidase mutants. Our results indicate that AlfC creates an aromatic subsite adjacent to the active site that specifically accommodates GlcNAc in α(1,6)-linkages, suggest that enzymatic activity is controlled by distinct open and closed conformations of an active-site loop, with certain mutations shifting the equilibrium towards open conformations to promote transfucosylation over hydrolysis, and provide a potentially generalizable framework for the rational creation of AlfC transfucosidase mutants.

PubMed: 33277506
DOI: 10.1038/s41467-020-20044-z

実験手法

X-RAY DIFFRACTION (2.55 Å)