| Primary Identifier | IPR038083 | Type | Homologous_superfamily |
| Short Name | NSP3A-like |
| description | The multi-domain non-structural protein NSP3 is the largest protein encoded by the coronavirus (CoV) genome, with an average molecular mass of about 200 kD. While some of the domains differ between CoV genera, eight domains of NSP3 exist in all known CoVs: the ubiquitin-like domain 1 (Ubl1), the Glu-rich acidic domain (also called "hypervariable region"), a macrodomain (also named "X domain"), the ubiquitin-like domain 2 (Ubl2), the papain-like protease 2 (PL2pro), the NSP3 ectodomain (3Ecto, also called "zinc-finger domain"), as well as the domains Y1 and CoV-Y of unknown functions. There are also two transmembrane regions, TM1 and TM2, which exist in all CoVs [].The ubiquitin-like domain 1 (Ubl1) and the Glu-rich acidic region are located at the N-terminal of NSP3. These two regions together are also named "NSP3A". In addition to the four β-strands and two α-helices that are common to ubiquitin-like folds, the globular domain of NSP3A contains two short helices []. NSP3A is well conserved within different SARS-CoV sequencesbut exhibits low sequence identity (less than 35%) to other CoV NSP3 proteins []. It is an essential component of the replication/transcription complex and is involved in multiple biological processes, such as proteolysis and RNA processing [].This entry represents NSP3A that has been shown to bind ssRNA. The overall structure of the SARS-CoV Ubl1 domain is similar to human ubiquitin (Ub) and that of each of the two ubiquitin-like domains of human or mouse interferon-stimulated gene 15 (hISG15 or mISG15). It is also similar to the Ras-interacting domain (RID) of RalGDS [, ]. |
