EC Number   |
General Information |
Reference |
|---|
   3.4.21.113 | physiological function |
cleavages downstream of NS3, NS4A, NS4B and NS5A, former parts of the viral polyprotein, are catalyzed by the serine protease domain of NS3 which requires NS4A as cofactor for full proteolytic activity and is termed NS3-4A protease. A special feature of pestiviruses is the existence of significant amounts of uncleaved NS2-3 in the infected cell and its essential role in virion formation, temporal restriction of NS2-3 processing by the NS2 autoprotease, mostly restricted to the early phase of infection. NS2-3 translated at later time points is only inefficiently processed leading to the accumulation of uncleaved NS2-3 which temporally correlates with the onset of virion morphogenesis. Downregulation of NS2-3 processing plays a crucial role for the non-cytopathogenic (ncp) biotype of pestiviruses in cell culture |
755207 |
| 3.4.21.113 | physiological function |
nonstructural protein 3, NS3, is a nonstructural protein possessing serine protease, helicase, and NTPase activity, it is a key player in virus replication. Ability of NS3 of classical swine fever virus to compensate for disabling size increase of core protein, role of NS3 in particle assembly, overview. In addition to its essential role in RNA replication, NS3 apparently organizes the incorporation of RNA into budding virus particles |
732796 |
| 3.4.21.113 | physiological function |
NS3 is a multifunctional enzyme and a natural fusion of an N-terminal chymotrypsin-like serine protease and a C-terminal nucleotide triphosphatase (NTPase)/helicase. All Flaviviridae NS3 proteases require a segment of another viral protein, NS4A for pestiviruses, as the structurally integrated essential cofactor, termed protease cofactor segment (PCS) to fulfill the protease function, and for pestiviruses the protease is responsible for the cleavage of all the linkages in the NS3-NS4A-NS4B-NS5A-NS5B region of the viral polyprotein. The enzyme is a natural protease-helicase fusion protein, structure-function analysis, overview. Analysis of the mechanism of NS3 helicase regulation by its fusion partner protease |
754554 |
| 3.4.21.113 | physiological function |
pivotal for processing of a large portion of the viral polyprotein is a serine protease activity within nonstructural protein 3 that also harbors helicase and NTPase activities essential forRNA replication |
732415 |
