Dengue virus non-structural protein 3 (NS3)

Dengue virus non-structural protein 3 (NS3) is a multifunctional enzyme essential for the replication and maturation of the Dengue virus (DENV). It contains two primary functional domains: an N-terminal serine protease that requires the NS2B protein as a cofactor for activity, and a C-terminal region with helicase, nucleoside triphosphatase (NTPase), and RNA triphosphatase (RTPase) activities [1, 2, 4]. The protease domain is responsible for the critical cleavage of the viral polyprotein into functional proteins, while the helicase domain facilitates viral RNA replication by unwinding double-stranded RNA intermediates [3, 9, 13]. As a conserved protein across all four Dengue serotypes and a major target for host cellular immunity, NS3 is a high-priority target for direct-acting antiviral development [1, 11]. Infection by Dengue virus can lead to conditions ranging from self-limiting fever to severe Dengue hemorrhagic fever, making the disruption of NS3-mediated replication a key clinical objective [4, 5]. Current therapeutic efforts involve small-molecule inhibitors designed to disrupt its enzymatic functions or its interactions with other viral proteins like NS4B and NS5 [4, 7, 10].

Other names

Non-structural protein 3NS3 proteinNS2B-NS3 protease complexNS3 protease-helicase

Competitive or allosteric inhibition of the NS2B-NS3 protease active site to prevent viral polyprotein cleavage; inhibition of the C-terminal helicase domain to block RNA unwinding; disruption of protein-protein interactions between NS3 and cofactors such as NS4B or NS5.