Protein Domain : Non-structural protein 3, X-domain-like IPR044371

Type	Domain
Description	The X-domain, a macrodomain, is found in riboviral non-structural protein 3 (NSP3), including the NSP3 of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and other coronaviruses (alpha-, beta-, gamma-, and deltacoronavirus), among others. The SARS-CoV X-domain may function as a module binding poly(ADP-ribose), a metabolic product of NAD+ synthesized by poly(ADP-ribose) polymerase (PARP) [ ]. The X-domain of Avian infectious bronchitis virus (IBV) strain Beaudette coronavirus does not bind ADP-ribose; the triple glycine sequence found in the X-domains of SARS-CoV and human coronavirus 229E (HCoV229E), which are involved in ADP-ribose binding, is not conserved in the IBV X-domain. SARS-CoV has two other macrodomains referred to as the SUD-N (N-terminal subdomain) and SUD-M (middle SUD subdomain) of the SARS-unique domain (SUD), which also do not bind ADP-ribose; these bind G-quadruplexes (unusual nucleic-acid structures formed by consecutive guanosine nucleotides) [].
Short Name	Macro_X_NSP3-like