Figure 1

NC protein is required for many replication steps. Mature NC molecules coat the genomic RNA, in a dimeric form, in the viral particle and thus exert an essential function in virion structure. As illustrated in this cartoon – courtesy of Dr. Lou Henderson (NCI-Frederick, MD, USA) – NC protein chaperones conversion of the genomic RNA into the viral DNA by the RT enzyme. NC is also involved in the maintenance of the newly made viral DNA and in its integration into the host genome to form the provirus. In the course of virus assembly, the NC domain of Gag pilots genomic RNA selection which in turn acts as a scaffold for Gag oligomerization and assembly. As highlighted in the top circle, the CCHC zinc finger is central to all the NC-mediated functions. Thus, the retroviral zinc finger motif is viewed as a major target in anti-HIV drug development.