helicase domain of coronavirus non-structural protein 13
This model represents the helicase domain of non-structural protein 13 (Nsp13) from alpha-, beta-, gamma-, and deltacoronavirus, including pathogenic human viruses such as Severe acute respiratory syndrome coronavirus (SARS-CoV), SARS-CoV2 (also called 2019 novel CoV or 2019-nCoV), and Middle East respiratory syndrome-related (MERS) CoV. Helicases catalyze NTP-dependent unwinding of nucleic acid duplexes into single strands and are classified based on the arrangement of conserved motifs into six superfamilies. CoV Nsp13 is a member of the helicase superfamily 1 (SF1); SF1 and SF2 helicases do not form toroidal structures, while SF3-6 helicases do. Nsp13 is a component of the viral RNA synthesis replication and transcription complex (RTC). It is a multidomain protein containing a Cys/His rich zinc-binding domain (CH/ZBD), a stalk domain, a 1B domain involved in nucleic acid substrate binding, and a SF1 helicase core.