Why I Do Science: Sydney Kustu
"I do science because at one time it was forbidden fruit. When I was a child, men had professions; women were assistants. As a young woman I developed a passion for understanding how cells replicate themselves, how they integrate their parts into a self-reproducing whole. To pursue this passion, I worked with the intestinal bacterium Escherichia coli. My lab explored its chemical conversions of nitrogen, an essential element. We were able to characterize new components of E. coli that are involved in acquiring nitrogen and sensing when this critical nutrient is scarce. Today we work with physicists at UC San Diego who are modeling nitrogen conversions in E. coli and studying the mechanisms that keep them in balance. We make and test predictions that should allow us to deepen our understanding.
"We were fortunate that our work with the nitrogen chemistry of E. coli led us to the Rh blood factor of humans. Molecular sequences now reveal distant evolutionary relationships between bacterial and human proteins. The Rh protein is abundant in the membranes of red blood cells. Although differences in its antigenicity are well known to cause immunological problems in blood transfusions between some mothers and their newborns, the primary function of Rh proteins had been unknown. By studying their microbial relatives, we’ve found that Rh proteins probably help humans and other animals dispose of carbon dioxide waste and keep their body fluids at neutral pH.
"Doing science has been sustaining and gratifying for me. There has been a great deal of change since I was recruited here from UC Davis in 1987, and the large number of young women scientists working in my department and in the College of Natural Resources today is heartening. As I think about the past, I am moved by a passage from T. S. Eliot:
"We shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time."