Author links open overlay panelChristophMeier¹²³A. RaduAricescu¹³ReneAssenberg²Robin T.Aplin²Robert J.C.Gilbert¹³Jonathan M.Grimes¹²³David I.Stuart¹²³

Summary

To achieve the greatest output from their limited genomes, viruses frequently make use of alternative open reading frames, in which translation is initiated from a start codon within an existing gene and, being out of frame, gives rise to a distinct protein product. These alternative protein products are, as yet, poorly characterized structurally. Here we report the crystal structure of ORF-9b, an alternative open reading frame within the nucleocapsid (N) gene from the SARS coronavirus. The protein has a novel fold, a dimeric tent-like β structure with an amphipathic surface, and a central hydrophobic cavity that binds lipid molecules. This cavity is likely to be involved in membrane attachment and, in mammalian cells, ORF-9b associates with intracellular vesicles, consistent with a role in the assembly of the virion. Analysis of ORF-9b and other overlapping genes suggests that they provide snapshots of the early evolution of novel protein folds.

For More Information: https://www.sciencedirect.com/science/article/pii/S0969212606002516