Investigating Phospholipid Transport in Gram-negative Bacteria, Michael Lee, UG '22, (3964281)
Gram-negative bacteria form two biological membranes; the inner membrane encloses the cytoplasm of the bacteria while the outer membrane surrounds the inner membrane and delineates the cell from the external environment. The outer membrane is an essential membrane for Escherichia coli, which is a model Gram-negative bacterium. Phospholipids are a necessary component of the outer membrane and are synthesized in the inner membrane or the cytoplasm. However, it is not known how phospholipids are transported and assembled into the outer membrane. In order to fill this gap in knowledge, my research investigated the inner membrane protein YhdP in its putative role as a transporter of phospholipids between the inner membrane and the outer membrane of Gram-negative bacteria. We conducted a mutational analysis where we generated mutations in regions of YhdP that resemble other putative phospholipid transporters. To gain more insight on how these mutations affect YhdP function and to see whether we could learn anything about YhdP from these mutations, we isolated suppressors of these mutations. From this study, we have a better understanding of the protein YhdP, its putative function in intermembrane phospholipid transport, and outer membrane biogenesis in general.