  When studying multi-body protein complexes, biochemists use computational
tools that can suggest hundreds or thousands of their possible spatial
configurations. However, it is not feasible to experimentally verify more than
only a very small subset of them. In this paper, we propose a novel multiscale
visual drilldown approach that was designed in tight collaboration with
proteomic experts, enabling a systematic exploration of the configuration
space. Our approach takes advantage of the hierarchical structure of the data
-- from the whole ensemble of protein complex configurations to the individual
configurations, their contact interfaces, and the interacting amino acids. Our
new solution is based on interactively linked 2D and 3D views for individual
hierarchy levels and at each level, we offer a set of selection and filtering
operations enabling the user to narrow down the number of configurations that
need to be manually scrutinized. Furthermore, we offer a dedicated filter
interface, which provides the users with an overview of the applied filtering
operations and enables them to examine their impact on the explored ensemble.
This way, we maintain the history of the exploration process and thus enable
the user to return to an earlier point of the exploration. We demonstrate the
effectiveness of our approach on two case studies conducted by collaborating
proteomic experts.
