The National Enterovirus Reference Laboratory of Australia plays an important role for surveillance of polio-like illness in children presenting as acute flaccid paralysis (AFP) in the Western Pacific Region. During the investigations of a case of AFP, a novel species A enterovirus was identified. Sequencing of the virus genome using primer walking methods, yielded data representing the complete capsid encoding region and non-structural protein 2A. Partial data representing the 5’NTR and non-structural protein 2B were also obtained. In 2013, the virus was designated as EV-A120 by the International Committee for the Taxonomy of Viruses. Phylogenetic analysis of EV-A120 indicated a close genetic relationship to Coxsackievirus A7, A14, A16 and also enterovirus A71. Both Coxsackievirus A7 and enterovirus A71 have been implicated in large outbreaks with a significant incidence of neurologic disease including acute flaccid paralysis.
Using the capsid encoding sequence of EV-A120, the amino acid sequence for the structural proteins VP1, VP2, VP3 and VP4 were deduced and comparative protein modelling methods applied to predict the 3-dimensional structure. These structures were then used for the in-silico reconstruction of the EV-A120 virus capsid. Using a BlueGene/Q supercomputer, housed at the Victorian Life Sciences Computation Initiative, atomistic molecular dynamics simulations were performed. These simulations represented the atomic structure of the virus capsid suspended in a saline environment at 37°C. Validation of the novel predictive modelling strategy, involved the in-silico reconstruction and simulation of enterovirus A71, subgenogroup C4a, with verification of the final structure confirmed by comparison to X-ray diffraction data derived from the public domain. The derivation of virus structural information using predictive modelling methods is a useful complementary method for experimentally derived data for novel and emerging pathogens, such as EV-A71 and EV-A120.