A novel PIV5-HN head domain dimer-of-dimers interface.

Abstract

<p>A) Cartoon representation of the PIV5-HN ectodomain structure dimer-of-dimers interface (DOD₂). Chains A and D are blue and green, respectively. Residues comprising the interface are shown as lighter color sticks, and residues that form disulfide bonds are colored tan. B) Contact map showing specific interactions within the interface. Gray, green, and red lines represent hydrophobic, electrostatic, and hydrogen bond interactions, respectively. Figure produced using the MONSTER server for analysis of macromolecular complexes <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003534#ppat.1003534-Salerno1" target="_blank">[52]</a>. C–D) Reducing and non-reducing SDS-PAGE gels, respectively, showing HN Cys mutants immunoprecipitated from cell extracts. The positions of monomer and dimer are indicated. The C111A mutation eliminates wt dimer formation. E) Flow cytometry reveals that each of the HN Cys mutants were expressed on the surface of cells within 2-fold of wt. MFI = mean fluorescence intensity. F) A cell-cell fusion assay indicates each of the HN Cys mutants remained fusogenic at levels similar to wt. Experiments were done in triplicate and error bars represent S.E.M in E–F.</p