Nonstructural proteins

Tai CL, Chi WK, Chen DS, Hwang LH (1996) The helicase activity associated with hepatitis C virus nonstructural protein 3 (NS3). J Virol 70 8477-8484 Tong X, Chase R, Skelton A, Chen T, Wright-Minogue J, Malcolm BA (2006) Identification and analysis of fitness of resistance mutations against the HCV protease inhibitor SCH 503034. Antiviral Res 70 28-38... 

Zhong W, Uss AS, Ferrari E, Lau JY, Hong Z (2000) De novo initiation of RNA synthesis by hepatitis C virus nonstructural protein 5B polymerase. J Virol 74 2017-2022 Zhou S, Yung Chan S, Cher Goh B, Chan E, Duan W, Huang M, McLeod HL (2005) Mechanism-based inhibition of cytochrome P450 3A4 by therapeutic drugs. Clin Pharma-cokinet 44 279-304... 

Fig. 2.1 (A) Structure of the HCV genome, with 5 - and 3 -untranslated regions and individual proteins of the polyprotein indicated Regions of the genome (approximately 3,000 bases) are drawn to scale. Structural protein regions are in light gray, nonstructural proteins in white, and untranslated regions in dark gray. (B) Structure of a typical replicon sequence, with the antibiotic resistance gene (Neo ) in place of the structural region and the second IRES (EMCV) inserted. The NS2 sequence is often rwt present in the replicon.

While we characterize nonstructural proteins as being globular in shape, these shapes vary considerably according to their use. Again, this overall shape is governed by a combination of factors including primary and secondary structures. 

AG Porter. Picornavirus nonstructural proteins emerging roles in virus replication and inhibition of host cell functions. J Virol 67 6917-6921, 1993. 

Fig. 14.1 The life cycle of coxsackievirus B3. CVB3 starts its life cycle by attaching to its receptor CAR and coreceptor DAF. Internalized virus releases its viral RNA, which can be used as the template for translation of polyprotein or transcription by RNA-dependent RNA polymerase 3D to replicate its genome. The polyprotein is self-cleaved by virus-encoded proteases to release structural proteins and nonstructural proteins. Later, structural proteins and viral RNA will assemble into progeny virions to be released from infected cell. Abbreviations CVB3, coxsackievirus B3 DAF, decay accelerating factor CAR, coxsackievirus and adenovirus receptor 3Dpo1, RNA-dependent RNA polymerase.

Hyatt AD, Zhao Y, Roy P (1993), Release of bluetongue virus-like particles from insect cells is mediated by BTV nonstructural protein NS3/NS3A, Virology 193 592-603. 

Mao, S.S. et al. 2008. A time-resolved, internally quenched fluorescence assay to characterize inhibition of hepatitis C virus nonstructural protein 3-4A protease at low enzyme concentrations. Anal Biochem. 373, 1-8. 

Caliciviridae— 340-A capsid of 180 proteins surrounding 7.5-kb genome several nonstructural proteins, nonenveloped. Structures for one of four genera... 

Gillian, A. L., and Nibert, M. L. (1998). Amino terminus of reovirus nonstructural protein sigma NS is important for ssRNA binding and nucleoprotein complex formation. Virology 240, 1-11. 

Schuck, P., Taraporewala, Z., McPhie, P., and Patton, J. T. (2001). Rotavirus nonstructural protein NSP2 self-assembles into octamers that undergo ligand-induced conformational changes. / Biol. Chem. 276, 9679-9687. 

Taraporewala, Z., Chen, D., and Patton, J. (2001). Multimers of the bluetongue virus nonstructural protein, NS2, possess nucleotidyl phosphatase activity Similarities between NS2 and rotavirus NSP2. Virology 280, 221-231. 

The alphaviruses are a group of 26 icosahedral, positive-sense RNA viruses primarily transmitted by mosquitoes [64]. These 700-A-diameter viruses are some of the simplest of the membrane-enveloped viruses, and members of this group cause serious tropical diseases with characteristic symptoms such as myositis, fever, rash, encephalitis, and polyarthritis [65]. The structures of two different alphavirus-Fab complexes have been determined by cryo-TEM Ross River virus (RR) and Sindbis virus (SIN) [66]. The amino acid sequences of the RR and SIN virus structural and nonstructural proteins are 49 and 64% identical, respectively [67]. The viral RNA genome and 240 copies of the capsid protein form the nucleocapsid core [68-73], and the El and E2 glycoproteins form heterodimers that associate as 80 trimeric spikes on the viral surface. Native SIN and RR lack the E3 glycoprotein because it disassociates from the spike complex after its display on the plasma membrane surface [74, 75]. El has a putative fusion domain that may facilitate host membrane penetration [76, 77]. E2 contains most of the neutralizing epitopes and is also probably involved in host cell recognition [78-80]. 

Bartenschlager, R., Ahlborn-Laake, L., Mous, J., and Jacobsen, H. (1993) Nonstructural protein 3 of the hepatitis C virus encodes a serine-type proteinase required for cleavage at the NS3/4 and NS4/5 junctions. J. Virol. 67,3835-3844. 

Fig. 2.1 The single-stranded DNA genome of AAV. The inverted terminal repeats (ITRs) flank the two open reading frames rep and cap. The rep gene encodes four nonstructural proteins -Rep78, Rep68, Rep52, and Rep40. The cap gene encodes three structural proteins - VPl, VP2, and VP3. The location of the promoters, p5, pl9, and p40 are depicted by arrows...

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