Enzymatic characterization and dominant sites of foot-and-mouth disease virus 2C protein
Saisai Zhou,
Nankun Liu,
Yang Tian,
Hong Pan,
Yang Han,
Zhen Li,
Jinhua Zhang,
Shuaiyin Guan,
Huanchun Chen,
Yunfeng Song
Affiliations
Saisai Zhou
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Nankun Liu
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Yang Tian
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Hong Pan
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Yang Han
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Zhen Li
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Jinhua Zhang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Shuaiyin Guan
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Huanchun Chen
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Yunfeng Song
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; Corresponding author. State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.
Foot-and-mouth disease virus (FMDV) 2C protein is a conserved non-structural protein and crucial for replication of the virus. In this study, FMDV 2C protein was prepared and the enzymatic activities were investigated in detail. The protein could digest ssDNA or ssRNA into a small fragment at about 10 nt, indicating that the protein has nuclease activity. But it did not show digestion to blunt-end dsDNA or dsRNA. The nuclease activity of 2C protein could be inhibited in 2 mM Zn2+ or Ca2+ while enhanced by Mg2+ or Mn2+. FMDV 2C protein exhibited unwinding activity to all the three kinds of dsDNA and dsRNA (5′ protruded, 3′ protruded, and blunt-end). The unwinding velocity to 5′ protruded dsRNA was higher than to the blunt-end dsRNA. 2C protein only showed unwinding activity in high concentration of Mg2+, but no unwinding activity in physiological concentrations of Mg2+ and Ca2+, as well as in cell lysate. The 2C protein could catalyze two structured ssRNA to form double strand, thus it was proved to have RNA chaperone activity. The Mg2+ and ATP in different concentrations did not show promotion to the RNA chaperone activity. Finally, six mutant proteins (K116A, D160A, D170A, N207A, R226A, and F316A) were constructed and the enzymatic activities were analyzed. All the six mutations reduced the ATPase activity, D170A and F361A could inactivate the nuclease activity, while the N207A and F316A could inactivate the helicase activity. Our study provides a comprehensive understanding of the enzymatic activities of FMDV 2C protein.
