 Its properties are similar to those of bacteriorhodopsin, and these two light-driven ion pumps transport cations and anions in opposite directions.Halorhodopsin isoforms can be found in multiple species of halobacteria, including "Halobacterium salinarum", and "Natronobacterium pharaonis".Much ongoing research is exploring these differences, and using them to parse apart the photocycle and pump properties.