Genomic and protein structure modelling analysis depicts the origin and pathogenicity of 2019-nCoV, a new coronavirus which caused a pneumonia outbreak in Wuhan, China [version 2; peer review: 2 not approved]

Background: A pandemic outbreak caused by a novel coronavirus, 2019-nCoV, has originated from Wuhan, China and spread to many countries around the world. The outbreak has led to around 45 thousand cases and over one thousand death so far. Methods: Phylogenetic analysis and sequence alignment were used to align the whole genome sequence of 2019-nCoV with other over 200 sequences of coronaviruses to predict the origin of this novel virus. In addition, protein modeling and analysis were performed to access the potential binding of the spike protein of 2019-nCoV with human cell receptor, angiotensin-converting enzyme 2 (ACE2). Results: Detailed genomic and structure-based analysis of a new coronavirus, namely 2019-nCoV, showed that the new virus is a new type of bat coronavirus and is genetically fairly distant from the human SARS coronavirus. Structure analysis of the spike (S) protein of this new virus showed that its S protein only binds much weaker to the ACE2 receptor on human cells whereas the human SARS coronavirus exhibits strongly affinity to the ACE receptor. Conclusions: These findings suggest that the new virus should theoretically not be able to cause very serious human infection when compared to human SARS virus. However, the lower pathogenicity of this new virus may lead to longer incubation time and better adaption to human, which may favor its efficient transmission in human. These data are important to guide design of infection control policy and inform the public on the nature of threat imposed by 2019-nCov. Most importantly, using the analysis platform that we have developed, we should be able to predict whether the new mutations could lead to the increase of infectivity of the mutated virus in a very short time.