Structure and dynamics of the N-terminal half of hepatitis C virus core protein: an intrinsically unstructured protein.

Hepatitis C virus core protein plays an important role in the assembly and packaging of the viral genome. We have studied the structure of the N-terminal half of the core protein (C82) which was shown to be sufficient for the formation of nucleocapsid-like particle (NLP) in vitro and in yeast. Structural bioinformatics analysis of C82 suggests that it is mostly unstructured. Circular dichroism and structural NMR data indicate that C82 lacks secondary structure. Moreover, NMR relaxation data shows that C82 is highly disordered. These results indicate that the N-terminal half of the HCV core protein belongs to the growing family of intrinsically unstructured proteins (IUP). This explains the tendency of the hepatitis C virus core protein to interact with several host proteins, a well-documented characteristic of IUPs.