Poster Presentation The 48th Lorne Conference on Protein Structure and Function 2023

Integrative structural approaches reveal dynamic interactions of NS2B-NS3 protease from DENV4  (#412)

Wint Wint Phoo 1 , Jun Ping Quek 2 3 4 , Zheng Ser 5 , Bing Liang Alvin Chew 2 3 4 , Xin Li 6 , Lili Wang 6 , Radoslaw M Sobota 5 , Dahai Luo 2 3 4
  1. Duke-NUS Graduate Medical School, Singapore, SINGAPORE
  2. School of Biological Sciences, Nanyang Technological University, Singapore
  3. Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
  4. Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore
  5. Functional Proteomics Laboratory, Institute of Molecular and Cell Biology, Singapore
  6. Singapore Laboratory for Mass spectrometry, Department of Biological Sciences, National University of Singapore, Singapore

Flavivirus such as dengue virus (DENV), West Nile Virus (WNV), are a serious threat to public health. The flavivirus single stranded RNA genome is translated into a polyprotein cleaved by viral and cellular proteases into three structural proteins and seven non-structural proteins. Non-structural (NS) protein 3 is a multifunctional protein with N-terminal protease and C-terminal helicase. The NS3 protease requires co-factor NS2B for enzymatic activity and folding. The NS2B-NS3 viral protease cleaves the viral polyprotein. Due to its essential role in viral replication, NS2B-NS3 protease is an attractive target for antiviral drugs. Despite availability of crystal structures, dynamic interactions of the N- and C-termini of NS2B co-factor have been elusive due to their flexible fold. In this study, we employ integrative structural approaches combined with biochemical assays to elucidate the interactions of flexible NS2B/3 N- and C-termini. We identified a novel cis-cleavage site between NS2B/NS3. Mapping of NS2B N- and C-termini with NS3 indicates that these interdomain interactions occur exclusively on the solvent exposed beta-barrel of NS3 protease domain. Our integrative approach enables a comprehensive understanding of the folding and dynamic interactions of DENV NS3 protease and its cofactor NS2B. 

  1. Quek, J.P., Ser, Z., Chew, B.L.A., Li, X., Wang, L., Sobota, R.M., Luo, D. and Phoo, W.W., 2022. Dynamic Interactions of Post Cleaved NS2B Cofactor and NS3 Protease Identified by Integrative Structural Approaches. Viruses, 14(7), p.1440.