BY THOMAS W. TRAUT

FOR ALMOST 50 YEARS Mary Ellen Jones was actively engaged in research related to amino acid metabolism and pyrimidine nucleotide metabolism. In collaboration with Leonard Spector she was a codiscoverer of carbamoyl phosphate, a compound essential for the biosynthesis of arginine and urea, and also for the biosynthesis of pyrimidine nucleotides. The discovery of carbamoyl phosphate was truly significant, as it rapidly influenced research in many other laboratories. An indicator of its importance is that within a few years it became commercially available. By the early 1970s she was among the first to define the new area of multifunctional proteins with her studies of dihydroorotate synthase (also called CAD) and UMP synthase. Jones continued to demonstrate talent for devising new analytical procedures, for cleverly designing experimental approaches, and for insightful analyses of the emerging information.

Jones was the first woman scientist to hold an endowed chair at the University of North Carolina and the first woman to become a department chair at the medical school. Jones was widely recognized for her scientific accomplishments and for her leadership roles. Among her awards were the Wilbur Lucius Cross Medal from Yale University (1982),