About the Cover: Structural model of the SARS Coronavirus Spike protein transmembrane domain, as modeled by molecular dynamics simulation in a hydrated lipid bilayer. The red trimeric helical bundle is embedded in the lipid bilayer with the aqueous environment seen above and below the membrane. The glycine residues forming the GxxxG motif are shown in ball and stick representation. The GxxxG motif is one of the driving forces behind the trimerization of the SARS Spike protein and as such is the first example of a GxxxG motif participating in trimerization of helical bundles. [Arbely, E., et al. (2006) Biochemistry 45, 11349-11356.] View the article.