Dengue 2 virus NS2B and NS3 form a stable complex that can cleave NS3 within the helicase domain
- PMID: 8460492
- DOI: 10.1006/viro.1993.1198
Dengue 2 virus NS2B and NS3 form a stable complex that can cleave NS3 within the helicase domain
Abstract
Flavivirus genomic RNA is translated into a large polyprotein that is processed into structural and nonstructural proteins. The N-termini of several nonstructural proteins are produced by cleavage at dibasic sites by a two-component viral proteinase consisting of NS2B and NS3. NS3 contains a trypsin-like serine proteinase domain at its N-terminus, whereas the function of NS2B in proteolysis is yet to be determined. We have used an NS3-specific antiserum, under nondenaturing conditions, to demonstrate that NS2B and NS3 form a complex both in vitro and in vivo. The N-terminal 184 residues of NS3 are sufficient to form the complex with NS2B. The complex forms efficiently when the NS2B and NS3 are translated from two different mRNAs as well as when NS2B and NS3 are translated as a polyprotein from the same mRNA. A chimeric complex can be formed between yellow fever NS2B and a chimeric yellow fever-dengue 2 NS3. Using anti-NS3 antisera, we also found that a 50-kDa fragment of NS3, consisting of the N-terminal approximately 460 residues, is produced in infected mammalian cells. This fragment is not produced in infected mosquito cells, but will form in Triton X-100 lysates of mosquito cells. The cleavage of NS3 to form this fragment is catalyzed by the NS3 proteinase itself and proteolysis requires NS2B. Examination of the amino acid sequence of NS3 reveals a potential conserved cleavage site that resembles other sites cleaved by the NS3/NS2B proteinase; this site occurs within a conserved RNA helicase sequence motif. The importance of this alternatively processed form of NS3 and its role in the replication cycle of dengue virus remain to be determined.
Similar articles
-
Yellow fever virus NS2B-NS3 protease: charged-to-alanine mutagenesis and deletion analysis define regions important for protease complex formation and function.Virology. 2000 Sep 30;275(2):335-47. doi: 10.1006/viro.2000.0488. Virology. 2000. PMID: 10998334
-
Mutagenesis of conserved residues at the yellow fever virus 3/4A and 4B/5 dibasic cleavage sites: effects on cleavage efficiency and polyprotein processing.Virology. 1993 Feb;192(2):596-604. doi: 10.1006/viro.1993.1076. Virology. 1993. PMID: 8421901
-
Identification of residues in the dengue virus type 2 NS2B cofactor that are critical for NS3 protease activation.J Virol. 2004 Dec;78(24):13708-16. doi: 10.1128/JVI.78.24.13708-13716.2004. J Virol. 2004. PMID: 15564480 Free PMC article.
-
Towards the design of antiviral inhibitors against flaviviruses: the case for the multifunctional NS3 protein from Dengue virus as a target.Antiviral Res. 2008 Nov;80(2):94-101. doi: 10.1016/j.antiviral.2008.07.001. Epub 2008 Jul 30. Antiviral Res. 2008. PMID: 18674567 Review.
-
The hepatitis C virus NS3 proteinase: structure and function of a zinc-containing serine proteinase.Antivir Ther. 1998;3(Suppl 3):99-109. Antivir Ther. 1998. PMID: 10726060 Review.
Cited by
-
Transmembrane Domains of NS2B Contribute to both Viral RNA Replication and Particle Formation in Japanese Encephalitis Virus.J Virol. 2016 May 27;90(12):5735-5749. doi: 10.1128/JVI.00340-16. Print 2016 Jun 15. J Virol. 2016. PMID: 27053551 Free PMC article.
-
Structure and function of the 3' terminal six nucleotides of the west nile virus genome in viral replication.J Virol. 2004 Aug;78(15):8159-71. doi: 10.1128/JVI.78.15.8159-8171.2004. J Virol. 2004. PMID: 15254187 Free PMC article.
-
Autocatalytic cleavage within classical swine fever virus NS3 leads to a functional separation of protease and helicase.J Virol. 2013 Nov;87(21):11872-83. doi: 10.1128/JVI.00754-13. Epub 2013 Aug 28. J Virol. 2013. PMID: 23986594 Free PMC article.
-
Both NS3 and NS4A are required for proteolytic processing of hepatitis C virus nonstructural proteins.J Virol. 1994 Jun;68(6):3753-60. doi: 10.1128/JVI.68.6.3753-3760.1994. J Virol. 1994. PMID: 8189513 Free PMC article.
-
Structure of the Flavivirus helicase: implications for catalytic activity, protein interactions, and proteolytic processing.J Virol. 2005 Aug;79(16):10268-77. doi: 10.1128/JVI.79.16.10268-10277.2005. J Virol. 2005. PMID: 16051820 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources