The light-driven proton pump proteorhodopsin enhances bacterial survival tough times

Abstract

Some microorganisms contain proteins that can interact with light and convert it into energy for growth and survival, or into sensory information that guides cells towards or away from light. The simplest energy-harvesting photoproteins are the rhodopsins, which consist of a single, membrane-embedded protein covalently bound to the chromophore retinal (a light-sensitive pigment) [1]. One class of archaeal photoproteins (called bacteriorhodopsin) was shown to function as a light-driven proton pump, generating biochemical energy from light [2,3]. For many years, these lightdriven proton pumps were thought to be found only in relatively obscure Archaea living in high salinity.