Some viruses, including hepatitis C virus (HCV), bypass cellular initiation factors and can initiate translation through an internal ribosomal entry site (IRES). This process is now examined for the HCV IRES, indicating that conformational changes are necessary but not sufficient for initiation. Instead, the initiator tRNA, but not its interaction with the start codon, seems key to stabilizing HCV mRNA binding to the ribosome, indicating that this IRES bypasses some, but not all, of the functions of the initiation factors.
- Christopher S Fraser
- John W B Hershey
- Jennifer A Doudna
