Protein Domain : Protein Z, RING-type zinc finger superfamily IPR038485

Type	Homologous_superfamily
Description	This entry represents the RING zinc finger domain of 'RING finger protein Z', a small polypeptide found in some negative-strand RNA viruses including Lassa fever virus, which plays a crucial role in virion assembly and budding. RING finger Z has been shown to interact with several host proteins, including promyelocytic leukemia protein and the eukaryotic translation initiation factor 4E [ , ]. It is sufficient in the absence of any other viral proteins to release virus-like particles from the infected cell []. This protein is also responsible for arenavirus superinfection exclusion; expression of this protein in a host cell strongly and specifically inhibits areanavirus transcription and replication [].The RING-finger is a specialised type of Zn-finger of 40 to 60 residues that binds two atoms of zinc, and is probably involved in mediating protein-protein interactions [ , , ]. There are two different variants, the C3HC4-type and a C3H2C3-type, which is clearly related despite the different cysteine/histidine pattern. The latter type is sometimes referred to as 'RING-H2 finger'. The RING domain is a protein interaction domain which has been implicated in a range of diverse biological processes. Several 3D-structures for RING-fingers are known [ , ]. The 3D structure of the zinc ligation system is unique to the RING domain and is referred to as the 'cross-brace' motif. The spacing of the cysteines in such a domain is:C-x(2)-C-x(9 to 39)-C-x(1 to 3)-H-x(2 to 3)-C-x(2)-C-x(4 to 48)-C-x(2)-C Metal ligand pairs one and three co-ordinate to bind one zinc ion, whilst pairs two and four bind the second.
Short Name	Z_RING-type_Znf_sf