The human pandemic coronaviruses on the show: the spike glycoprotein as the main actor in the coronaviruses play

Abstract

Three coronaviruses (CoVs) have threatened theworld population by causing outbreaks in the last two decades. In late 2019, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged and caused the coronaviruses to disease 2019 (COVID-19), leading to the ongoing global outbreak. The other pandemic coronaviruses, SARS-CoV and Middle East respiratory syndrome CoV (MERS-CoV), share a considerable level of similarities at genomic and protein levels. However, the differences between them lead to distinct behaviors. These differences result from the accumulation of mutations in the sequence and structure of spike (S) glycoprotein, which plays an essential role in coronavirus infection, pathogenicity, transmission, and evolution. In this review, we brought togethermany studies narrating a sequence of events and highlighting the differences among S proteins fromSARS-CoV, MERS-CoV, and SARS-CoV-2. Itwas performed here, analysis of S protein sequences and structures from the three pandemic coronaviruses pointing out the mutations among them and what they come through. Additionally, we investigated the receptor-binding domain (RBD) from all S proteins explaining themutation and biological importance of all of them. Finally,we discuss the mutation in the S protein fromseveral newisolates of SARS-CoV-2, reporting their difference and importance. This reviewbrings into detail howthe variations in S protein that make SARS-CoV-2more aggressive than its relatives coronaviruses and other differences between coronaviruses.