Abstract Per-ARNT-Sim (PAS) domains of proteins play important roles as modules for
signalling and cellular regulation processes in widely diverse organisms such as Archaea,
Bacteria, protists, plants, yeasts, insects and vertebrates. These domains are present in
many proteins where they are used as sensors of stimuli and modules for protein
interactions. Characteristically, they can bind a broad spectrum of molecules. Such binding
causes the domain to trigger a specific cellular response or to make the protein containing …