Meta-Biol

• Pathways

nsp13 is an ATP-dependent human SARS coronavirus 1 (SARS-CoV-1) helicase that functions in the 5'-3' direction to unwind double stranded RNAs that have a 5' single strand overhang at least 20 nucleotides long. nsp13 can also act on double strand DNA in vitro, but dsRNA is thought to be its physiological substrate. The catalytic activity of nsp13 is increased in the presence of nsp12, the viral RNA-dependent RNA polymerase. nsp13 is needed for the replication of SARS-CoV-1 and is thought to act by melting secondary structures in the genomic RNA template during replication, and also to be involved in unwinding of RNA duplexes during transcription of viral genes. nsp13 is a promising target for experimental anti-SARS-CoV-1 drugs (Tanner et al. 2003, Ivanov et al. 2004, Bernini et al. 2006, Chen et al. 2009, Lee et al. 2010, Adedeji et al. 2012).