Complexes consisting of proteins and small molecule cofactors are ubiquitous and vitally important for many processes in all organisms. For each, an appropriate ratio of protein and cofactor is required for normal cellular function. In humans, protein-cofactor imbalances are potentially linked to diseases including Alzheimer’s, porphyrias, and retinitis pigmentosa.
To better understand how proper balance of proteins and cofactors are maintained, we study a simple complex in the halophilic microbe Halobacterium salinarum. In H. salinarum, the bacterioopsin protein combines with a retinal cofactor to form the bacteriorhodopsin complex. Bacteriorhodopsin catalyzes the conversion of light energy into usable energy for the cell. Bacteriorhodopsin homologs are found in all domains of life suggesting that mechanisms associated with its production might also be widely distributed. We previously identified a novel mechanism in which bacterioopsin, when not bound by retinal, inhibits a key enzyme in an alternate biochemical pathway so that shared precursor molecules are preserved for retinal synthesis. We are currently exploring if this novel mechanism is present in other organisms that produce rhodopsins.
Dr. Peck is Assistant Professor of Biology at Colby College.
Audience: Scientific and Medical Community.