title: Membrane topology of NS2B of dengue virus revealed by NMR spectroscopy.
abstract: Non-structural (NS) proteins of dengue virus (DENV) are important for viral replication. There are four membrane proteins that are coded by viral genome. NS2B was shown to be one of the membrane proteins and its main function was confirmed to regulate viral protease activity. Its membrane topology is still not known because only few studies have been conducted to understand its structure. Here we report the determination of membrane topology of NS2B from DENV serotype 4 using NMR spectroscopy. NS2B of DENV4 was expressed and purified in detergent micelles. The secondary structure of NS2B was first defined based on backbone chemical resonance assignment. Four helices were identified in NS2B. The membrane topology of NS2B was defined based on relaxation analysis and paramagnetic relaxation enhancement experiments. The last three helices were shown to be more stable than the first helix. The NS3 protease cofactor region between α2 and α3 is highly dynamic. Our results will be useful for further structural and functional analysis of NS2B.
authors.affiliation: Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore.
authors.forename: Qingxin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore.
authors.forename: Ying Lei
authors.initials: YL
authors.lastname: Wong
authors.affiliation: Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore.
authors.forename: Lynette Sin Yee
authors.initials: LS
authors.lastname: Liew
authors.affiliation: Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore. Electronic address: cbkang@etc.a-star.edu.sg.
authors.forename: CongBao
authors.initials: C
authors.lastname: Kang
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry* / Q000648:ultrastructure*; D003716:Dengue Virus / Q000378:metabolism* / Q000648:ultrastructure; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: C080102:NS2B protein, flavivirus; D017361:Viral Nonstructural Proteins
keywords: Dengue virus; Membrane protein; NMR; NS2B; Protein dynamics