title: Mutagenesis analysis of porcine reproductive and respiratory syndrome virus nonstructural protein 7.
abstract: Nonstructural protein 7 (nsp7), which is flanked by nsp6 and nsp8, is one of the most conserved nonstructural proteins of porcine reproductive and respiratory syndrome virus (PRRSV). Nonstructural protein (nsp)-specific antibodies are produced in high titers in response to virus replication, especially against nsp1a, nsp1b, nsp2, and nsp7. However, many regional aspects of nsp7 are still veiled, such as its impact on viral replication and virulence or the immunological mechanism between virus and host. Based on the structure of the predicted nsp7 domain, we have constructed a series of large mutations and deletions. We ultimately demonstrated all mutations (nsp7, nsp7α/nspβ) and the majority of substitutions of nsp7 affected the PRRSV replicative cycle in some ways and were fatal for viral recovery, which indicates that these are significant to structure or function of the nsp7. What's more, the mutant vOKXH-nsp7 (F40A) indeed caused some of the variation compared with the parental virus vOKXH-GD, which shortens the amount of time needed to reach its highest viral titer, and decreases the concentration of the highest viral titer, obstructing viral mRNA and protein synthesis. Consequently, these valuable results possibly provide the first direct evidence that the nsp7 is really a critical protein domain for the RNA synthesis and the translation of viral protein of PRRSV.
authors.affiliation: MOA Key Laboratory of Animal Vaccine Development, Ministry of China, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Road, Tianhe District, Guangzhou, 510642, China.
authors.forename: Minze
authors.initials: M
authors.lastname: Zhang
authors.forename: Zhenpeng
authors.initials: Z
authors.lastname: Cao
authors.forename: Jiexiong
authors.initials: J
authors.lastname: Xie
authors.forename: Wanjun
authors.initials: W
authors.lastname: Zhu
authors.forename: Pei
authors.initials: P
authors.lastname: Zhou
authors.forename: Honglang
authors.initials: H
authors.lastname: Gu
authors.forename: Long
authors.initials: L
authors.lastname: Sun
authors.forename: Shuo
authors.initials: S
authors.lastname: Su
authors.forename: Guihong
authors.initials: G
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D008969:Molecular Sequence Data; D016296:Mutagenesis; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics* / Q000502:physiology; D016415:Sequence Alignment; D013552:Swine; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics*; D014779:Virus Replication
chemical_list: D017361:Viral Nonstructural Proteins
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