# Comparative analysis of deep mutational scanning datasets in enteroviruses A and B identifies functional divergence and therapeutic targets

## TL;DR

Comparing mutational data from two enterovirus species reveals shared and distinct evolutionary constraints, offering insights into viral evolution and potential drug targets.

## Contribution

A framework for analyzing evolutionary constraints at multiple scales using comparative deep mutational scanning in enteroviruses.

## Key findings

- Species-level constraints are found in core enzymatic machinery and capsid assembly interfaces.
- Type-specific constraints are observed at host-interaction sites in structural and non-structural proteins.
- A mutationally constrained pocket in the 2C helicase is conserved across major human enterovirus species.

## Abstract

Deep mutational scanning (DMS) can define functional constraints acting on viral proteomes by quantifying the effects of mutations on viral fitness. However, DMS analyses do not discern type-specific from species-level constraints, limiting their utility in understanding how selective pressures change as viral families diversify. Here we show that comparison of DMS datasets from related viruses can overcome these limitations. By contrasting two proteome-wide DMS datasets from prototypical members of the enterovirus A and B species, we identify evolutionary constraints at the species level to occur across core enzymatic machinery and capsid assembly interfaces. In contrast, type-level constraints are observed across host-interaction sites in both structural and non-structural proteins. Furthermore, we find DMS data to reflect both type- and species-level evolutionary signatures in nature yet diverge at conserved hotspots subjected to selection pressures that are lacking in vitro. Finally, we highlight the utility of comparative DMS studies for drug discovery by identifying a mutationally constrained pocket in the 2C helicase that is conserved across all major human enterovirus species. Our findings provide a framework for dissecting evolutionary pressures acting at different evolutionary scales and for guiding the rational design of broad-spectrum therapeutics with high barriers to resistance.

A comparison of proteome-wide mutational scanning datasets from enterovirus A and B species reveals evolutionary constraints shared by these viral species that localize to core functional regions, as well as species- and type-specific constraints that map to distinct host interactions.