Membrane topology of NS2B of dengue virus revealed by NMR spectroscopy

• Published in: Biochimica et biophysica acta 2015-10, Vol.1848 (10), p.2244-2252
• Main Authors: Li, Yan, Li, Qingxin, Wong, Ying Lei, Liew, Lynette Sin Yee, Kang, CongBao
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Cell Membrane - chemistry; Cell Membrane - ultrastructure; Dengue virus; Dengue Virus - metabolism; Dengue Virus - ultrastructure; Magnetic Resonance Spectroscopy - methods; Membrane protein; Models, Chemical; Models, Molecular; Molecular Sequence Data; NMR; NS2B; Protein Conformation; Protein dynamics; Viral Nonstructural Proteins - chemistry; Viral Nonstructural Proteins - ultrastructure
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2015.06.010

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. [Display omitted] •Backbone assignment of dengue NS2B in LMPG was obtained.•Dengue NS2B contains four helices.•Membrane topology of NS2B was proposed.•The cofactor region is flexible in micelles.