Crystallographic snapshots of the EF-hand protein MCFD2 complexed with the intracellular lectin ERGIC-53 involved in glycoprotein transport
Crystallographic snapshots of the EF-hand protein MCFD2 complexed with the intracellular lectin ERGIC-53 involved in glycoprotein transport
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DOI：
10.1107/s2053230x20005452
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发表时间：
2020-05-01
影响因子：
0.9
通讯作者：
Kato, Koichi
中科院分区：
文献类型：
--
作者：
Satoh, Tadashi;Nishio, Miho;Kato, Koichi
跨膜细胞内凝集素ER-高尔基体中室蛋白53（ERGIC-53）和可溶性EF-手多凝血因子缺陷蛋白2（MCFD 2）形成复合物，其作为货物受体起作用，在内质网（ER）和高尔基体之间运输各种糖蛋白。已经证明ERGIC-53的碳水化合物识别结构域（CRD）（ERGIC-53（CRD））与货物糖蛋白上的N-连接聚糖相互作用，而MCFD 2识别货物糖蛋白的多肽区段。与MCFD 2和甘露糖基寡糖复合的ERGIC-53（CRD）的晶体结构揭示了蛋白质-蛋白质和蛋白质-糖结合模式。相比之下，MCFD 2的多肽识别机制在很大程度上仍然未知。在此，报告了ERGIC-53（CRD）-MCFD 2复合物的1.60埃分辨率晶体结构，沿着还有三种其它晶体形式。这些结构与先前报道的那些结构的比较揭示MCFD 2，而不是ERGIC-53-CRD，表现出显著的构象可塑性，这可能与其对各种多肽配体的调节有关。
The transmembrane intracellular lectin ER-Golgi intermediate compartment protein 53 (ERGIC-53) and the soluble EF-hand multiple coagulation factor deficiency protein 2 (MCFD2) form a complex that functions as a cargo receptor, trafficking various glycoproteins between the endoplasmic reticulum (ER) and the Golgi apparatus. It has been demonstrated that the carbohydrate-recognition domain (CRD) of ERGIC-53 (ERGIC-53(CRD)) interacts with N-linked glycans on cargo glycoproteins, whereas MCFD2 recognizes polypeptide segments of cargo glycoproteins. Crystal structures of ERGIC-53(CRD) complexed with MCFD2 and mannosyl oligosaccharides have revealed protein-protein and protein-sugar binding modes. In contrast, the polypeptide-recognition mechanism of MCFD2 remains largely unknown. Here, a 1.60 angstrom resolution crystal structure of the ERGIC-53(CRD) -MCFD2 complex is reported, along with three other crystal forms. Comparison of these structures with those previously reported reveal that MCFD2, but not ERGIC-53-CRD, exhibits significant conformational plasticity that may be relevant to its accommodation of various polypeptide ligands.