MERS coronavirus envelope protein has a single transmembrane domain that forms pentameric ion channels

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly identified pathogen able of human transmission that causes a mortality of almost 40%. As in the case of SARS-CoV, MERS virus lacking E protein represents a potential vaccine. In both cases, abolishment of channel activity may be a contributor to the attenuation observed in E-deleted viruses. Herein, we report that purified MERS-CoV E protein, like SARS-CoV E protein, is almost fully α-helical, has a single α-helical transmembrane domain, and forms pentameric ion channels in lipid bilayers. Based on these similarities, and the proposed involvement of channel activity as virulence factor in SARS-CoV E protein, MERS-CoV E protein may constitute a potential drug target.