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K160 in the RNA‐binding domain of the orf virus virulence factor OV20.0 is critical for its functions in counteracting host antiviral defense
Author(s) -
Liao GuanRu,
Tseng YeuYang,
Tseng ChingYu,
Huang YingPing,
Tsai ChingHsiu,
Liu HaoPing,
Hsu WeiLi
Publication year - 2021
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.14099
Subject(s) - protein kinase r , rna silencing , biology , rna , rna interference , virulence , eif 2 kinase , virus , microbiology and biotechnology , host factor , virology , protein kinase a , kinase , genetics , gene , mitogen activated protein kinase kinase , cyclin dependent kinase 2
The OV20.0 virulence factor of orf virus antagonizes host antiviral responses. One mechanism through which it functions is by inhibiting activation of the dsRNA‐activated protein kinase R (PKR) by sequestering dsRNA and by physically interacting with PKR. Sequence alignment indicated that several key residues critical for dsRNA binding were conserved in OV20.0, and their contribution to OV20.O function was investigated in this study. We found that residues F141, K160, and R164 were responsible for the dsRNA‐binding ability of OV20.0. Interestingly, mutation at K160 (K160A) diminished the OV20.0–PKR interaction and further reduced the inhibitory effect of OV20.0 on PKR activation. Nevertheless, OV20.0 homodimerization was not influenced by K160A. The contribution of the dsRNA‐binding domain and K160 to the suppression of RNA interference by OV20.0 was further demonstrated in plants. In summary, K160 is essential for the function of OV20.0, particularly its interaction with dsRNA and PKR that ultimately contributes to the suppression of PKR activation.