Expression and Dimerization of Hepatitis C Virus Core Protein in E. coli

Hepatitis C virus (HCV) is a positive-stranded RNA virus with a genome size of about 9–10 kb. The genome of this virus encodes a polyprotein with a length of over 3000 amino acids. This polyprotein is cleaved by cellular and viral proteases to generate at least 10 viral gene products. Recent reports have indicated that there are extensive interactions between various HCV proteins: the core (capsid) protein can interact with itself (1 ) and with the El envelope protein (2 ); El protein can interact with the E2 envelope protein (3 ,4 ) which in turn can be covalently linked to its following p7 protein and interact with another integral membrane protein named NS2 (5 ); NS2 can also interact with NS5A and NS5B nonstructural proteins (6 ); and NS3 proteinase/helicase has also been shown to complex with the NS4A protein (6 ,7 ). Thus, most of the known HCV proteins interact with at least another HCV protein. These interactions are presumably very important for morphogenesis and replication of HCV.