Dr. George Mackie is Professor of Biochemistry and Molecular Biology. His research team investigates the properties of the relevant enzymes and RNA chaperones, the functional state of the mRNA and the secondary or tertiary structure of the RNA substrate determine its fate. Model systems are employed for investigating this process using appropriate biochemical and molecular biological tools. Their goal is to explain how the properties of the relevant enzymes and RNA chaperones, the functional state of the mRNA (e.g., its efficiency of translation) and the secondary or tertiary structure of the RNA substrate determine its fate. Turnover of mRNA in Escherichia coli is believed to be initiated by specific endonucleolytic cleavages followed by exonucleolytic “scavenging” of the newly created 3′ ends. We have cloned, over-expressed, and purified the key ribonucleases as well as several accessory proteins including an RNA helicase and RNA chaperones. A major success has been the reconstitution of mRNA degradation in vitro from purified enzymes and substrates.