Inhibition of viral group-1 and group-2 neuraminidases by oseltamivir: A comparative structural analysis by the ScrewFit algorithm

The viral surface glycoprotein neuraminidase (NA) allows the influenza virus penetration and the egress of virions. NAs are classified as A, B, and C. Type-A NAs from influenza virus are subdivided into two phylogenetically distinct families, group-1 and group-2. NA inhibition by oseltamivir represents a therapeutic approach against the avian influenza virus H5N1. Here, structural bases for oseltamivir recognition by group-1 NA1, NA8 and group-2 NA9 are highlighted by the ScrewFit algorithm for quantitative structure comparison. Oseltamivir binding to NA1 and NA8 affects the geometry of Glu119 and of regions Arg130-Ser160, Val240-Gly260, and Asp330-Glu382, leading to multiple NA conformations. Additionally, although NA1 and NA9 share almost the same oseltamivir-bound final conformation, they show some relevant differences as suggested by the ScrewFit algorithm. These results indicate that the design of new NA inhibitors should take into account these family-specific effects induced on the whole structure of NAs.