The outbreak of a novel coronavirus associated with acute respiratory disease, called COVID-19, marked the introduction of the third spillover of an animal coronavirus (CoV) to humans in the last two decades. The genome analysis with various bioinformatics tools revealed that the causative pathogen (SARS-CoV-2) belongs to the subgenus Sarbecovirus of the genus Betacoronavirus, with highly similar genome as bat coronavirus and receptor-binding domain (RBD) of spike glycoprotein as Malayan pangolin coronavirus. Based on its genetic proximity, SARS-CoV-2 is likely to have originated from bat-derived CoV and transmitted to humans via an unknown intermediate mammalian host, probably Malayan pangolin. Further, spike protein S1/S2 cleavage site of SARS-CoV-2 has acquired polybasic furin cleavage site which is absent in bat and pangolin suggesting natural selection either in an animal host before zoonotic transfer or in humans following zoonotic transfer. In the current review, we recapitulate a preliminary opinion about the disease, origin and life cycle of SARS-CoV-2, roles of virus proteins in pathogenesis, commonalities, and differences between different corona viruses. Moreover, the crystal structures of SARS-CoV-2 proteins with unique characteristics differentiating it from other CoVs are discussed. Our review also provides comprehensive information on the molecular aspects of SARS-CoV-2 including secondary structures in the genome and protein-protein interactions which can be useful to understand the aggressive spread of the SARS-CoV-2. The mutations and the haplotypes reported in the SARS-CoV-2 genome are summarized to understand the virus evolution.

中文翻译：

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SARS-CoV-2，大流行性冠状病毒：分子和结构见解

一种与急性呼吸道疾病相关的新型冠状病毒（称为 COVID-19）的爆发，标志着过去二十年来动物冠状病毒（CoV）第三次向人类蔓延。利用多种生物信息学工具进行基因组分析显示，致病病原体（SARS-CoV-2）属于β冠状病毒属的Sarbecovirus亚属，其基因组与蝙蝠冠状病毒高度相似，刺突糖蛋白受体结合结构域（RBD）与马来穿山甲高度相似。冠状病毒。根据其遗传相似性，SARS-CoV-2 很可能起源于蝙蝠衍生的 CoV，并通过未知的中间哺乳动物宿主（可能是马来穿山甲）传播给人类。此外，SARS-CoV-2 的刺突蛋白 S1/S2 裂解位点获得了蝙蝠和穿山甲中不存在的多元弗林蛋白酶裂解位点，这表明在人畜共患病转移之前的动物宿主中或在人畜共患转移后的人类中存在自然选择。在当前的综述中，我们概述了关于 SARS-CoV-2 的疾病、起源和生命周期、病毒蛋白在发病机制中的作用、不同冠状病毒之间的共性和差异的初步意见。此外，还讨论了 SARS-CoV-2 蛋白的晶体结构，该蛋白具有区别于其他 CoV 的独特特征。我们的综述还提供了有关 SARS-CoV-2 分子方面的全面信息，包括基因组中的二级结构和蛋白质-蛋白质相互作用，这有助于了解 SARS-CoV-2 的侵袭性传播。总结 SARS-CoV-2 基因组中报告的突变和单倍型，以了解病毒的进化。