Han Xiao PhD thesis - Research@StAndrews:FullText - University of ...

species. The expression of P/V/C proteins involves “RNA editing” that alters the ORFs
by insertion of G residues at a specific position in the mRNA. In the case of PIV5 P
protein, it is the translation product from mRNA that is generated by the addition of two
non-templated G residues at the editing site of the V/P gene that shift the ORFs at the site
of insertion.
The P protein C-terminal polymerase cofactor module is relatively well conserved, and is
well studied for its role in viral RNA synthesis. P protein functions as a homo-oligomer,
and the multimerization of P protein is mediated by its C-terminus domain. P protein also
functions as a bridge to link L polymerase with the NP-RNA template. The C-terminal
domain of P protein contains binding motif for interaction with L protein and for binding
to the N-RNA complex (Bowman, Smallwood, and Moyer, 1999; Curran, Pelet, and
Kolakofsky, 1994; Ryan, Morgan, and Portner, 1991).
1.2.5.3 The V protein
The V protein is encoded by the P/V gene and shares an N-terminal domain with the P
protein but has a distinct C-terminal domain. The C-terminal domain of V protein is
highly conserved and there is high sequence similarity among different paramyxoviruses.
It contains a zinc-binding domain that binds two zinc molecules per V protein (Fukuhara
et al., 2002; Li et al., 2006a). It has been proposed that the “Zinc-finger” domain is
perhaps involved in interaction of V protein with other proteins. PIV5 V protein is a
structural protein that is incorporated into the virion (approximately 350 copies of V
protein per virion) and is associated with the nucleocapsids, whilst for respiroviruses and
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