Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
Nat Chem Biol. 2017 Jul;13(7):757-763. doi: 10.1038/nchembio.2381. Epub 2017 May 22.
Protein O-fucosyltransferase 1 (POFUT1) fucosylates the epidermal growth factor (EGF)-like domains found in cell-surface and secreted glycoproteins including Notch and its ligands. Although Notch fucosylation is critical for development, and POFUT1 deficiency leads to human disease, how this enzyme binds and catalyzes the fucosylation of its diverse EGF-like domain substrates has not been determined. Reported here is the X-ray crystal structure of mouse POFUT1 in complex with several EGF-like domains, including EGF12 and EGF26 of Notch. Overall shape complementarity, interactions with invariant atoms of the fucosylation motif and flexible segments on POFUT1 all define its EGF-like-domain binding properties. Using large-scale structural and sequence analysis, we also show that POFUT1 binds EGF-like domains of the hEGF type and that the highly correlated presence of POFUT1 and fucosylatable hEGFs has accompanied animal evolution.
蛋白-O-岩藻糖基转移酶 1（POFUT1）在包括 Notch 及其配体在内的细胞表面和分泌糖蛋白的表皮生长因子（EGF）样结构域上进行岩藻糖基化。虽然 Notch 的岩藻糖基化对于发育至关重要，且 POFUT1 的缺乏会导致人类疾病，但该酶如何结合并催化其各种 EGF 样结构域底物的岩藻糖基化尚未确定。本文报道了小鼠 POFUT1 与多个 EGF 样结构域（包括 Notch 的 EGF12 和 EGF26）复合物的 X 射线晶体结构。整体形状互补、与岩藻糖基化基序不变原子的相互作用以及 POFUT1 上的柔性片段都定义了其 EGF 样结构域结合特性。通过大规模的结构和序列分析，我们还表明 POFUT1 结合 hEGF 型的 EGF 样结构域，并且 POFUT1 和可岩藻糖基化的 hEGF 的高度相关存在伴随着动物的进化。
