How does the new coronavirus recombine in nature? Another bat coronavirus newly discovered in Xishuangbanna Tropical Botanical Garden of Chinese Academy of Sciences in Yunnan Province provides new clues for Chinese and foreign scientists to understand this puzzle.
It is found that there are multiple amino acid insertions in S1 and S2 subunits of spike protein of bat coronavirus, which reveals the natural insertions of S1 / S2 shear sites of S protein of new coronavirus (hcov-19) and the possible recombination sources of new coronavirus. S protein is the key to the binding of new coronavirus to human cell receptor ACE2, which is equivalent to the “key” to enter human cells. The insertion of the above-mentioned cut site was previously considered by conspiracy theorists as artificial intervention.
The above scientific research results are from the joint scientific research team of China and foreign countries, including the first Medical University of Shandong, the laboratory of etiology and epidemiology of new infectious diseases of Shandong University, Xishuangbanna Tropical Botanical Garden of Chinese Academy of Sciences, Beijing Institute of life sciences of Chinese Academy of Sciences, Wuhan virus research Institute of Chinese Academy of Sciences, Institute of Microbiology of Chinese Academy of Sciences and Sydney University of Australia The paper has not yet been peer reviewed.
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In this paper, the research team reported a new bat derived coronavirus, named rmyn02, which was identified from genome analysis of 227 bats collected in Yunnan Province of China from May to October 2019.
The novel coronavirus HCoV-19 and RmYN02 have a homology of 93.3% in the whole genome and 97.2% in the closest 1ab gene to HCoV-19. In contrast, rmyn02 receptor binding domain (RBD) has a low sequence homology with hcov-19 (61.3%), which may not bind to ACE2.
However, similar to hcov-19, rmyn02 is characterized by the insertion of multiple amino acids at the shear sites of S1 and S2 subunits of S protein. According to the research team, this strongly proves that this kind of insertion event can occur in nature.
These data suggest that hcov-19 is derived from multiple natural recombination of viruses present in bats and other wildlife.
The corresponding authors of this paper are Shi Weifeng, director of the Institute of pathogenic biology, School of basic medicine, Shandong First Medical University, director of the laboratory of etiology and epidemiology of new infectious diseases of Shandong University, Bi Yuhai, group leader and project researcher of the research group of virus transmission early warning and pathogenic mechanism, Institute of Microbiology, Chinese Academy of Sciences, and Bi Yuhai, comprehensive protection center of Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Alice Catherine Hughes, group leader and associate professor of landscape ecology.
The origin of new coronavirus is not clear, and there are still a large number of coronaviruses in wild animals
Hcov-19 has caused an unprecedented epidemic of pneumonia in China and other regions, which has attracted worldwide public health attention. Although bats are considered to be the most likely natural hosts of hco19, the origin of the virus is still unclear.
According to the epidemiological investigation of several cases of hcov-19 in the early stage of the epidemic, most people had visited the South China seafood market in Wuhan before the onset of the epidemic. The market has a variety of wild animals for sale, which was finally closed on January 1, 2020.
A novel coronavirus is different from SARS-CoV and MERS-CoV by phylogenetic analysis. HCoV-19 is a new type of coronavirus. So far, the virus most closely related to hcov-19 is ratg13, which was isolated from a Chinese Rhinolophus specimen collected in Yunnan Province by Shi Zhengli team of Wuhan Institute of viruses, Chinese Academy of Sciences in 2013. Ratg13 strain and new coronavirus have 96.1% nucleotide homology and 92.9% s gene homology. These data once again show that bats are important hosts of coronavirus.
However, it should be noted that Professor Guan Yi, National Key Laboratory of emerging infectious diseases, School of public health, University of Hong Kong, Professor Hu Yanling, Guangxi Medical University, and Professor Shen Yongyi, Professor Xiao Lihua, Professor Shen Yongyi, Guangdong Provincial Laboratory of modern agricultural science and technology, South China Agricultural University, and Guangdong Provincial Laboratory of modern agricultural science and technology, all reported the relevant hcov-19 crown in pangolin, Malaysia These pangolins are illegally smuggled into Guangxi and Guangdong.
The team noted that although the coronaviruses detected in these pangolins are much farther away from hcov-19 than ratg13, they are very similar to hcov-19 in the receptor binding domain (RBD) of the S protein.
Therefore, although it is not clear whether pangolins are intermediate hosts for the transmission of hco19 to humans, they may play an important role in the ecology and evolution of coronaviruses.
They believe that the viruses found in pangolin can show that there are still a large number of coronavirus samples in wild animals, some of which may be directly involved in the emergence of hcov-19.
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Sequence comparison between hcov-19 and several representative bat derived coronaviruses.
A new bat derived coronavirus named rmyn02