Fast Enzyme Has Fatty Ancestry

A study of the origin of one of nature’s most efficient enzymes could have implications for better understanding and influencing the way plants produce oils (Nature, DOI: 10.1038/nature11009). Chalcone isomerase (CHI) is an nearly perfect enzyme because it catalyzes flavonoid production almost instantaneously in the presence of chalcone substrate. The enzyme’s evolutionary provenance now suggests CHI is related to protiens that manage fatty acid metabolism. Eve Syrkin Wurtele of Iowa State University, Joseph P. Noel of the Salk Institute for Biological Studies, and coworkers have carried out gene sequence comparison and structural studies that show noncatalytic fatty-acid-binding proteins (FABPs) to be CHI’s evolutionary predecessors. In the study, the group obtained crystal structures of two FABPs and compared them with that of CHI, which Noel’s group obtained over a decade ago. The structures revealed that FABPs bind fatty acids in a pocket similar to the one CHI uses to bind chalcone. According to Noel, “the work has implications for modulating plant fatty acid profiles,” which impact the use of plants as sources of food oils, biorenewable chemicals, and biofuels.