SARS-CoV-2 nsp9 Products

SARS-CoV-2 Nonstructural Protein 9 (NSP9) is one of the sixteen nonstructural proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19 (1). SARS-CoV-2 NSP9 is 113 amino acids (aa) with a theoretical molecular weight of 12.4 kDa (1-3). The amino acid sequence alignment of SARS-CoV and SARS-CoV-2's NSP9 has 97.3% sequence identity and 99.1% sequence similarity (1). Structurally NSP9 has a N-terminal beta-barrel made of seven beta-strands and a C-terminal alpha-helix (3). In SARS-CoV, NSP9 is important for viral proliferation; it is unclear if NSP9 plays the same role in SARS-CoV-2 but given the high degree of sequence similarity it is quite likely (4). SARS-CoV-2 NSP9 also plays a role in formation of nuclear transport machinery and the extracellular matrix (2). Additionally, NSP9 binds mind bomb 1 (MIB1), an E3 ubiquitin ligase that regulates antiviral innate immune signaling (2).

References

1. Yoshimoto F. K. (2020). The Proteins of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2 or n-COV19), the Cause of COVID-19. The protein journal. https://doi.org/10.1007/s10930-020-09901-4

2. Gordon, D. E., Jang, G. M., Bouhaddou, M., Xu, J., Obernier, K., White, K. M., O'Meara, M. J., Rezelj, V. V., Guo, J. Z., Swaney, D. L., Tummino, T. A., Huttenhain, R., Kaake, R. M., Richards, A. L., Tutuncuoglu, B., Foussard, H., Batra, J., Haas, K., Modak, M., Kim, M., ... Krogan, N. J. (2020). A SARS-CoV-2 protein interaction map reveals targets for drug repurposing. Nature. https://doi.org/10.1038/s41586-020-2286-9

3. Qiu, Y., & Xu, K. (2020). Functional studies of the coronavirus nonstructural proteins. STEMedicine. https://doi.org/10.37175/stemedicine.v1i2.39

4. Khan, M. T., Irfan, M., Ahsan, H., Ahmed, A., Kaushik, A. C., Khan, A. S., Chinnasamy, S., Ali, A., & Wei, D. Q. (2021). Structures of SARS-CoV-2 RNA-Binding Proteins and Therapeutic Targets. Intervirology. Advance online publication. https://doi.org/10.1159/000513686