2WV9

Crystal Structure of the NS3 protease-helicase from Murray Valley encephalitis virus

Summary for 2WV9

• Entry DOI: 10.2210/pdb2wv9/pdb
• Related: 2V8O
• Descriptor: FLAVIVIRIN PROTEASE NS2B REGULATORY SUBUNIT, FLAVIVIRIN PROTEASE NS3 CATALYTIC SUBUNIT (2 entities in total)
• Functional Keywords: nucleotide-binding, capsid protein, rna replication, envelope protein, virion, helicase, hydrolase, flavivirus, nucleotidyltransferase
• Biological source: MURRAY VALLEY ENCEPHALITIS VIRUS
• Cellular location: Capsid protein C: Virion (Potential). Peptide pr: Secreted (By similarity). Small envelope protein M: Virion membrane; Multi-pass membrane protein (By similarity). Envelope protein E: Virion membrane; Multi- pass membrane protein (By similarity). Non-structural protein 1: Secreted. Non-structural protein 2A: Host endoplasmic reticulum membrane; Multi-pass membrane protein (Potential). Serine protease subunit NS2B: Host endoplasmic reticulum membrane; Multi-pass membrane protein (Potential). Serine protease NS3: Host endoplasmic reticulum membrane; Peripheral membrane protein; Cytoplasmic side (By similarity). Non-structural protein 4A: Host endoplasmic reticulum membrane; Multi-pass membrane protein (By similarity). Non-structural protein 4B: Host endoplasmic reticulum membrane; Multi-pass membrane protein (By similarity). RNA-directed RNA polymerase NS5: Host endoplasmic reticulum membrane; Peripheral membrane protein; Cytoplasmic side (By similarity): P05769
• Total number of polymer chains: 1
• Total formula weight: 74056.55

Authors

Assenberg, R.,Mastrangelo, E.,Walter, T.S.,Verma, A.,Milani, M.,Owens, R.J.,Stuart, D.I.,Grimes, J.M.,Mancini, E.J. (deposition date: 2009-10-15, release date: 2009-12-01, Last modification date: 2023-12-20)

Primary citation

Assenberg, R.,Mastrangelo, E.,Walter, T.S.,Verma, A.,Milani, M.,Owens, R.J.,Stuart, D.I.,Grimes, J.M.,Mancini, E.J.
Crystal Structure of a Novel Conformational State of the Flavivirus Ns3 Protein: Implications for Polyprotein Processing and Viral Replication.
J.Virol., 83:12895-, 2009

PubMed Abstract: The flavivirus genome comprises a single strand of positive-sense RNA, which is translated into a polyprotein and cleaved by a combination of viral and host proteases to yield functional proteins. One of these, nonstructural protein 3 (NS3), is an enzyme with both serine protease and NTPase/helicase activities. NS3 plays a central role in the flavivirus life cycle: the NS3 N-terminal serine protease together with its essential cofactor NS2B is involved in the processing of the polyprotein, whereas the NS3 C-terminal NTPase/helicase is responsible for ATP-dependent RNA strand separation during replication. An unresolved question remains regarding why NS3 appears to encode two apparently disconnected functionalities within one protein. Here we report the 2.75-A-resolution crystal structure of full-length Murray Valley encephalitis virus NS3 fused with the protease activation peptide of NS2B. The biochemical characterization of this construct suggests that the protease has little influence on the helicase activity and vice versa. This finding is in agreement with the structural data, revealing a single protein with two essentially segregated globular domains. Comparison of the structure with that of dengue virus type 4 NS2B-NS3 reveals a relative orientation of the two domains that is radically different between the two structures. Our analysis suggests that the relative domain-domain orientation in NS3 is highly variable and dictated by a flexible interdomain linker. The possible implications of this conformational flexibility for the function of NS3 are discussed.

PubMed: 19793813
DOI: 10.1128/JVI.00942-09

Experimental method

X-RAY DIFFRACTION (2.75 Å)