Methyltransferases/metabolism; Severe Acute Respiratory Syndrome/virology; Severe acute respiratory syndrome-related coronavirus/enzymology; Viral Nonstructural Proteins/metabolism; Adaptor Proteins, Signal Transducing; Amino Acid Motifs; Animals; Carrier Proteins/genetics; Carrier Proteins/metabolism; DEAD-box RNA Helicases/genetics; DEAD-box RNA Helicases/metabolism; Female; Humans; Interferon-Induced Helicase, IFIH1; Male; Methyltransferases/chemistry; Methyltransferases/genetics; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mutation; RNA-Binding Proteins; Severe acute respiratory syndrome-related coronavirus/genetics; Severe acute respiratory syndrome-related coronavirus/pathogenicity; Severe acute respiratory syndrome-related coronavirus/physiology; Severe Acute Respiratory Syndrome/genetics; Severe Acute Respiratory Syndrome/metabolism; Viral Nonstructural Proteins/chemistry; Viral Nonstructural Proteins/genetics; Virulence; Virus Replication