Acta Veterinaria et Zootechnica Sinica ›› 2024, Vol. 55 ›› Issue (5): 2061-2071.doi: 10.11843/j.issn.0366-6964.2024.05.024

• PREVENTIVE VETERINARY MEDICINE • Previous Articles     Next Articles

Prokaryotic Expression and Protein Activity of Porcine Circovirus Type 3 Rep

HAN Yang, GUAN Shuaiyin, LI Zhen, ZHOU Saisai, YUAN Honggen, SONG Yunfeng*   

  1. College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
  • Received:2023-07-20 Online:2024-05-23 Published:2024-05-27

Abstract: Rep protein plays an important role in porcine circovirus replication. This study aimed to analyze the endonuclease activity,ATPase activity and helicase activity of porcine circovirus type 3(PCV3)Rep protein. The recombinant proteins were purified by Ni2+ affinity column chromatography. We established an enzymatic activity assay of Rep protein by optimizing the reaction conditions,and the key active site of Rep protein was explored. Our results confirmed that Rep has endonuclease activity、ATPase activity and helicase activity in vitro. Rep protein exhibited optimal ATPase activity in reaction with 1.6 μmol·L-1 Rep and 1 mmol·L-1 Mg2+ at 37 ℃ for 75 min. It exhibited optimal ATPase activity in reaction with 7 μmol·L-1 Rep and 12.5 mmol·L-1 Mg2+ at 37 ℃ for 75 min. Y89 of PCV3 Rep was essential for its endonuclease activity. And K173, D210, N250 sites were essential for its ATPase and helicase activities. In this paper, we developed a method for analysis of the enzyme activity and preliminarily revealed the main functional sites of PCV3 Rep protein,which laid a foundation for the functional study of PCV3 Rep protein and the development of antiviral drugs based on the activity of Rep protein.

Key words: porcine circovirus type 3, Rep, endonuclease activity, ATPase activity, helicase activity

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