Structure and oligomerization state of the C‐terminal region of the Middle East respiratory syndrome coronavirus nucleoprotein

Nguyen, Thi Hong Van; Lichière, Julie; Canard, Bruno; Papageorgiou, Nicolas; Attoumani, Sarah; Ferron, François; Coutard, Bruno

Middle East respiratory syndrome coronavirus (MERS‐CoV) is a human pathogen responsible for a severe respiratory illness that emerged in 2012. Structural information about the proteins that constitute the viral particle is scarce. In order to contribute to a better understanding of the nucleoprotein (N) in charge of RNA genome encapsidation, the structure of the C‐terminal domain of N from MERS‐CoV obtained using single‐crystal X‐ray diffraction is reported here at 1.97 Å resolution. The molecule is present as a dimer in the crystal structure and this oligomerization state is confirmed in solution, as measured by additional methods including small‐angle X‐ray scattering measurements. Comparisons with the structures of the C‐terminal domains of N from other coronaviruses reveals a high degree of structural conservation despite low sequence conservation, and differences in electrostatic potential at the surface of the protein.