Structure of SARS-CoV-2 envelope protein solved by NMR

At just 75 amino acids long, the envelope (E) protein is the smallest of the four structural proteins that make up the SARS-CoV-2 viral particle and is essential for the virus to infect cells. Data from other coronaviruses led researchers to assume that groups of five E proteins formed a pore spanning the virus’s lipid bilayer membrane. But direct evidence did not exist, as structural characterization of membrane-spanning proteins is tricky with the most commonly used techniques—X-ray crystallography and cryo-electron microscopy. Mei Hong’s group at the Massachusetts Institute of Technology instead used nuclear magnetic resonance spectroscopy to solve the E protein’s structure and confirm the pore formation (Nat. Struct. Mol. Biol. 2020, DOI: 10.1038/s41594-020-00536-8). The group also studied how two drugs, amantadine and hexamethylene amiloride, can bind to and block the pore. Although those drugs bind to the pore weakly, the researchers say the new structural information may help in designing drugs that target the virus.