Correspondence

Dengue virus causes dengue haemorrhagic fever or dengue shock syndrome with a high mortality rate. The genome of dengue virus is a positive-sense, single-stranded RNA encoding three structural and seven non-structural proteins. The core protein is one of the three structural proteins and is the building block of the nucleocapsid of dengue virus. The core protein of dengue virus type 2 (DEN2) is composed of 100 aa with four a-helix domains. An internal hydrophobic domain located at aa 44–60 was identified. The DEN2 core protein was shown to form homodimers. Deletion of aa 1–36 or 73–100 decreased but did not completely abolish the core-to-core homotypic interaction, whereas deletion of a portion (aa 44–60) within aa 37–72 completely abolished the ability of the DEN2 core proteins to interact with each other. A recombinant DEN2 core protein corresponding to aa 37–72 was able to undergo homotypic interaction and bound to a native DEN2 core protein. The results of this study indicated that the homotypic interaction domain of the DEN2 core protein is located at aa 37–72 and that the internal hydrophobic domain located at aa 44–60 plays a pivotal role in core-to-core homotypic interaction