ENGINEERING SIGNAL SEQUENCES ON THE N-TERMINUS OF SALMONELLA ENTERICA: 1,2-PROPANEDIOL UTILIZATION MICROCOMPARTMENT PROTEINS
Kamaria Kermah1, Christopher Jakobson2, Danielle Tullman-Ercek2.
1El Camino College, Torrance, CA, 2University of California, Berkeley, Berkeley, CA.
The Pdu (1,2-propanediol utilization) microcompartment is a complex protein chamber that encases a specialized metabolic pathway that Salmonella enterica uses for its pathogenicity in the human gut. This unique packaging system can be effectively engineered for industrial use as a nanobioreactor or molecule transporter. Pdu microcompartments localize diol dehydratase (PduCDE), an enzyme complex encoded by the pduCDE genes. This enzyme complex contains a signal sequence on the PduD protein that promotes encapsulation. The N-terminal of the PduD protein contains a hydrophobic motif that serves as signal sequences that localizes diol dehydratase. The variability of this hydrophobic pattern is of importance in engineering microcompartments. Through homologous recombination, numerous signal sequences with corresponding hydrophobic faces were engineered into the 5´ end of pduD genes. Cells were grown simultaneously and selected on 1,2-propanediol-infused media. The growth rate of the cells will be compared to that of wild-type Salmonella enterica cells by optical densities. By assessing the surviving cell’s genome, we will clarify the role of protein patterns in localization. This information can be used for engineering synthetic microcompartments to produce biofuels, clean forms of energy, and chemicals of interest.