Dimerization of retroviral RNA genomes : an inseparable pair

Many viruses carry more than one segment of nucleic acid into the virion particle, but retroviruses are the only known group of viruses that contain two identical (or nearly identical) copies of the RNA genome within the virion. These RNA genomes are non-covalently joined together through a process known as genomic RNA dimerization. Uniquely, the RNA dimerization of the retroviral genome is of crucial importance for efficient retroviral replication. In this article, our current understanding of the relationship between retroviral genome conformation, dimerization and replication is reviewed.