PROSITE documentation PDOC51436
Potyvirus NIa protease (NIa-pro) domain profile


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 [1]. 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 [3].

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>) [3].

The profile we developed covers the entire potyvirus NIa-pro domain.

Last update:

August 2011 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

POTYVIRUS_NIA_PRO, PS51436; Potyvirus NIa protease (NIa-pro) domain profile  (MATRIX)


1AuthorsZheng N. Perez J. de J. Zhang Z. Dominguez E. Garcia J.A. Xie Q.
TitleSpecific and efficient cleavage of fusion proteins by recombinant plum pox virus NIa protease.
SourceProtein Expr. Purif. 57:153-162(2008).
PubMed ID18024078

2AuthorsDaros J.-A. Carrington J.C.
TitleRNA binding activity of NIa proteinase of tobacco etch potyvirus.
SourceVirology 237:327-336(1997).
PubMed ID9356344

3AuthorsPhan J. Zdanov A. Evdokimov A.G. Tropea J.E. Peters H.K. III Kapust R.B. Li M. Wlodawer A. Waugh D.S.
TitleStructural basis for the substrate specificity of tobacco etch virus protease.
SourceJ. Biol. Chem. 277:50564-50572(2002).
PubMed ID12377789



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