2l8k
From Proteopedia
NMR Structure of the Arterivirus nonstructural protein 7 alpha (nsp7 alpha)
Structural highlights
FunctionRPOA_EAVBU The replicase polyprotein 1ab is a multifunctional protein: it contains the activities necessary for the transcription of negative stranded RNA, leader RNA, subgenomic mRNAs and progeny virion RNA as well as proteinases responsible for the cleavage of the polyprotein into functional products.[1] Nsp1 is essential for viral subgenomic mRNA synthesis.[2] Nsp2 cysteine proteinase which cleaves the nsp2/nsp3 site in the polyprotein. Also displays deubiquitinating and deISGylase activities. The deubiquitinating activity cleaves both ubiquitinated and ISGylated products and may therefore regulate ubiquitin and ISG15 dependent host innate immunity.[3] The 3C-like serine proteinase chain is responsible for the majority of cleavages as it cleaves the C-terminus of the polyprotein.[4] The helicase chain, which contains a zinc finger structure, displays RNA and DNA duplex-unwinding activities with 5' to 3' polarity.[5] Publication Abstract from PubMedArterivirus replicase polyproteins are cleaved into at least 13 mature nonstructural proteins (nsps), and in particular the nsp5-to-nsp8 region is subject to a complex processing cascade. The function of the largest subunit from this region, nsp7, which is further cleaved into nsp7alpha and nsp7beta, is unknown. Using nuclear magnetic resonance (NMR) spectroscopy, we determined the solution structure of nsp7alpha of equine arteritis virus, revealing an interesting unique fold for this protein but thereby providing little clue to its possible functions. Nevertheless, structure-based reverse genetics studies established the importance of nsp7/nsp7alpha for viral RNA synthesis, thus providing a basis for future studies. Structure and Genetic Analysis of the Arterivirus Nonstructural Protein 7{alpha}.,Manolaridis I, Gaudin C, Posthuma CC, Zevenhoven-Dobbe JC, Imbert I, Canard B, Kelly G, Tucker PA, Conte MR, Snijder EJ J Virol. 2011 Jul;85(14):7449-53. Epub 2011 May 11. PMID:21561912[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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