Activation and maturation of SARS-CoV main protease

The worldwide outbreak of the severe acute respiratory syndrome (SARS) in 2003 was due to the transmission of SARS coronavirus (SARS-CoV). The main protease (M^pro) of SARS-CoV is essential for the viral life cycle, and is considered to be an attractive target of anti-SARS drug development. As a key enzyme for proteolytic processing of viral polyproteins to produce functional non-structure proteins, M^pro is first auto-cleaved out of polyproteins. The monomeric form of M^pro is enzymatically inactive, and it is activated through homo-dimerization which is strongly affected by extra residues to both ends of the mature enzyme. This review provides a summary of the related literatures on the study of the quaternary structure, activation, and self-maturation of M^pro over the past years.