Pangolins have been suggested as potential reservoir of zoonotic viruses, including SARS-CoV-2 causing the global COVID-19 outbreak. Here, we study the binding of two SARS-CoV-2-like viruses isolated from pangolins, GX/P2V/2017 and GD/1/2019, to human angiotensin-converting enzyme 2 (hACE2), the receptor of SARS-CoV-2. We find that the spike protein receptor-binding domain (RBD) of pangolin CoVs binds to hACE2 as efficiently as the SARS-CoV-2 RBD in vitro. Furthermore, incorporation of pangolin CoV RBDs allows entry of pseudotyped VSV particles into hACE2-expressing cells. A screen for binding of pangolin CoV RBDs to ACE2 orthologs from various species suggests a broader host range than that of SARS-CoV-2. Additionally, cryo-EM structures of GX/P2V/2017 and GD/1/2019 RBDs in complex with hACE2 show their molecular binding in modes similar to SARS-CoV-2 RBD. Introducing the Q498H substitution found in pangolin CoVs into the SARS-CoV-2 RBD expands its binding capacity to ACE2 homologs of mouse, rat, and European hedgehog. These findings suggest that these two pangolin CoVs may infect humans, highlighting the necessity of further surveillance of pangolin CoVs.

中文翻译：

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跨物种 ACE2 与穿山甲来源的 SARS-CoV-2 样病毒相互作用的分子基础


穿山甲被认为是人畜共患病毒的潜在宿主，其中包括导致全球 COVID-19 爆发的 SARS-CoV-2。在这里，我们研究了从穿山甲中分离出的两种 SARS-CoV-2 样病毒 GX/P2V/2017 和 GD/1/2019 与人血管紧张素转换酶 2 (hACE2)（SARS-CoV 的受体）的结合。 2.我们发现穿山甲冠状病毒的刺突蛋白受体结合结构域（RBD）在体外与 hACE2 的结合效率与 SARS-CoV-2 RBD 相同。此外，穿山甲冠状病毒 RBD 的掺入允许假型 VSV 颗粒进入表达 hACE2 的细胞。对穿山甲 CoV RBD 与不同物种的 ACE2 直向同源物结合的筛选表明，其宿主范围比 SARS-CoV-2 更广泛。此外，与 hACE2 复合的 GX/P2V/2017 和 GD/1/2019 RBD 的冷冻电镜结构显示其分子结合模式类似于 SARS-CoV-2 RBD。将穿山甲冠状病毒中发现的 Q498H 取代引入 SARS-CoV-2 RBD 中，可扩展其与小鼠、大鼠和欧洲刺猬的 ACE2 同源物的结合能力。这些发现表明这两种穿山甲冠状病毒可能感染人类，凸显了进一步监测穿山甲冠状病毒的必要性。