|PROSITE documentation PDOC51436|
Tobacco etch virus (TEV), tomato vein mottling virus (TVMV), and plum pox virus (PPV) are members of the Potyviridae family [E1]. The potyvirus genome is a (+) stranded RNA and is translated into a single polyprotein upon infection, which is processed by the virally encoded proteases P1, HC-Pro, and NIa. Most of the cleavage events are performed by NIa (nuclear inclusion protein a) protease (NIa-pro). NIa-pro processes seven sites present in the potyvirus polyprotein, named as A, B, C, D, V, E, and F. NIa-pros obtained from potyviruses have similar structures and functions. The potyvirus NIa-pro has a His-Asp-Cys catalytic triad, which is homologous to the trypsin-like proteases (see <PDOC00124>) except for Cys replacing Ser. NIa-pros obtained from potyviruses share certain sequence identities; however they recognize distinct amino acid sequences at each recognition sites. Consequently, they cannot recognize the cleavage sites of each other efficiently . Nia-pro belongs to peptidase family C4 [E2]. In addition to the catalytic activity NIa-pro possesses also sequence non-specific RNA-binding activity and RNA polymerase (NIb) binding activity .
The potyvirus NIa protein contains the following two domains; the VPg domain at the N-terminus and the NIa-pro domain at the C-terminus [1,2]. The ~250-amino acid NIaPro domain adopts the characteristic two-domain antiparallel β-barrel fold that is the hallmark of trypsin-like serine proteases, with the catalytic triad residues His, Asp, and Cys located at the interface between domains (see <PDB:1LVM>) .
The profile we developed covers the entire potyvirus NIa-pro domain.Last update:
August 2011 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Zheng N. Perez J. de J. Zhang Z. Dominguez E. Garcia J.A. Xie Q.|
|Title||Specific and efficient cleavage of fusion proteins by recombinant plum pox virus NIa protease.|
|Source||Protein Expr. Purif. 57:153-162(2008).|
|2||Authors||Daros J.-A. Carrington J.C.|
|Title||RNA binding activity of NIa proteinase of tobacco etch potyvirus.|
|3||Authors||Phan J. Zdanov A. Evdokimov A.G. Tropea J.E. Peters H.K. III Kapust R.B. Li M. Wlodawer A. Waugh D.S.|
|Title||Structural basis for the substrate specificity of tobacco etch virus protease.|
|Source||J. Biol. Chem. 277:50564-50572(2002).|