7nt8
Influenza virus H3N2 nucleoprotein - R416A mutant
Structural highlights
FunctionGST26_SCHJA Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. GST isoenzymes appear to play a central role in the parasite detoxification system. Other functions are also suspected including a role in increasing the solubility of haematin in the parasite gut.NCAP_I68A6 Encapsidates the negative strand viral RNA, protecting it from nucleases. The encapsidated genomic RNA is termed the ribonucleoprotein (RNP) and serves as template for transcription and replication. The RNP needs to be localized in the host nucleus to start an infectious cycle, but is too large to diffuse through the nuclear pore complex. NP comprises at least 2 nuclear localization signals that are responsible for the active RNP import into the nucleus through cellular importin alpha/beta pathway. Later in the infection, nclear export of RNPs are mediated through viral proteins NEP interacting with M1 which binds nucleoproteins. It is possible that nucleoprotein binds directly host exportin-1/XPO1 and plays an active role in RNPs nuclear export. M1 interaction with RNP seems to hide nucleoprotein's nuclear localization signals. Soon after a virion infects a new cell, M1 dissociates from the RNP under acidification of the virion driven by M2 protein. Dissociation of M1 from RNP unmasks nucleoprotein's nuclear localization signals, targeting the RNP to the nucleus.[HAMAP-Rule:MF_04070] Publication Abstract from PubMedInfluenza A viruses of the H1N1 and H3N2 subtypes are responsible for seasonal epidemic events. The influenza nucleoprotein (NP) binds to the viral genomic RNA and is essential for its replication. Efforts are under way to produce therapeutics and vaccines targeting the NP. Despite this, no structure of an NP from an H3N2 virus has previously been determined. Here, the structure of the A/Northern Territory/60/1968 (H3N2) influenza virus NP is presented at 2.2 A resolution. The structure is highly similar to those of the A/WSN/1933 (H1N1) and A/Hong Kong/483/97 (H5N1) NPs. Nonconserved amino acids are widely dispersed both at the sequence and structural levels. A movement of the 73-90 RNA-binding loop is observed to be the key difference between the structure determined here and previous structures. The data presented here increase the understanding of structural conservation amongst influenza NPs and may aid in the design of universal interventions against influenza. Structure of an H3N2 influenza virus nucleoprotein.,Knight ML, Fan H, Bauer DLV, Grimes JM, Fodor E, Keown JR Acta Crystallogr F Struct Biol Commun. 2021 Jul 1;77(Pt 7):208-214. doi:, 10.1107/S2053230X2100635X. Epub 2021 Jun 29. PMID:34196611[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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