Because of its plant-type photosynthetic mechanism, the availability of convenient procedures for reverse genetics and the knowledge of the nucleotide sequence of its complete genome, this cyanobacterial species provides a model system to study photosynthesis. The Chitnis laboratory has used targeted gene inactivation to generate many subunit-specific mutants of photosystem I and has identified functions of photosystem I proteins. Characterization of mutant photosystem I complexes is performed in collaboration with some distinguished spectroscopists around the world. In another collaborative project, the structure of photosystem I from a thermophilic cyanobacterium is studied using a multidisciplinary combination of crystallography, protein chemistry and molecular genetics. Dr. Chitnis is also studying degradation of membrane proteins.
Protein degradation is an essential component of normal cellular homeostasis.
During metabolism in a cell, the damaged proteins need to be degraded. Protein degradation in plant leaves is a crucial factor in recycling of amino acids during seed filling. Protein degradation is also essential to remove regulatory proteins or enzymes that are no longer necessary. Thus protein degradation is essential for the survival and death of a cell and for the biogenesis and degeneration of its membrane-bound compartments. Mechanism of degradation of membrane proteins is not known.