The crystal structure of the F protein (prefusion form) of the paramyxovirus parainfluenza virus 5 (PIV5) WR isolate was determined. We investigated the basis by which point mutations affect fusion in PIV5 isolates W3A and WR, which differ by two residues in the F ectodomain. The P22 stabilizing site acts through a local conformational change and a hydrophobic pocket interaction, whereas the S443 destabilizing site appears sensitive to both conformational effects and amino acid charge/polarity changes.
Copyright © 2015, American Society for Microbiology. All Rights Reserved.