Complex sentence: Since the initial discovery the PAS domain, a large quantity of PAS domain binding sites have been discovered in bacteria and eukaryotes, a subset called PAS LOV proteins, which are responsive to oxygen, light and voltage.
Split into simpler sentences: Since the initial discovery of the PAS domain, a large quantity of PAS domain binding sites have been discovered in bacteria and eukaryotes. A subset called PAS LOV proteins are responsive to oxygen, light and voltage.