KEGG   ENZYME: 3.4.22.44Help
Entry
EC 3.4.22.44                Enzyme                                 

Name
nuclear-inclusion-a endopeptidase;
potyvirus NIa protease
Class
Hydrolases;
Acting on peptide bonds (peptidases);
Cysteine endopeptidases
BRITE hierarchy
Reaction(IUBMB)
Hydrolyses glutaminyl bonds, and activity is further restricted by preferences for the amino acids in P6 - P1' that vary with the species of potyvirus, e.g. Glu-Xaa-Xaa-Tyr-Xaa-Gln!(Ser or Gly) for the enzyme from tobacco etch virus. The natural substrate is the viral polyprotein, but other proteins and oligopeptides containing the appropriate consensus sequence are also cleaved.
Comment
The potyviruses cause diseases in plants, and inclusion bodies appear in the host cell nuclei; protein a of the inclusion bodies is the endopeptidase. The enzyme finds practical use when encoded in vectors for the artificial expression of recombinant fusion proteins, since it can confer on them the capacity for autolytic cleavage. It is also reported that transgenic plants expressing the enzyme are resistant to viral infection. Type example of peptidase family C4.
History
EC 3.4.22.44 created 2000
Reference
1
  Authors
Fellers, J.P., Collins, G.B. and Hunt, A.G.
  Title
The NIa-proteinase of different plant potyviruses provides specific resistance to viral infection.
  Journal
Crop Sci. 38 (1998) 1309-1319.
Reference
2
  Authors
Kim, D.-H. and Choi, K.Y.
  Title
Potyvirus NIa protease.
  Journal
In: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Eds.), Handbook of Proteolytic Enzymes, Academic Press, London, 1998, p. 721-723.
Reference
3  [PMID:9648226]
  Authors
Takahashi T, Nakanishi M, Yao Y, Uyeda I, Serizawa N.
  Title
Direct formation of human interleukin-11 by cis-acting system of plant virus protease in Escherichia coli.
  Journal
Biosci. Biotechnol. Biochem. 62 (1998) 953-8.
  Organism
clover yellow vein virus
Reference
4  [PMID:8955037]
  Authors
Kim DH, Hwang DC, Kang BH, Lew J, Han J, Song BD, Choi KY.
  Title
Effects of internal cleavages and mutations in the C-terminal region of NIa protease of turnip mosaic potyvirus on the catalytic activity.
  Journal
Virology. 226 (1996) 183-90.
  Organism
turnip mosaic potyvirus
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
139946-51-3

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