Kristy Morales, M.D.
Education: Bachelor of Arts in biology (May 2004)
Doctor of Medicine from Creighton University Medical School
McNair Project: Investigation of Possible Interactions of Proteins LEF-8 and LEF-9 in the Virally Encoded RNA Polymerase (2003)
Mentor: Lorena Passarelli, Ph.D.
The Autographa californica M nuclopolyhedrosis (AcMNPV) late expression factor-9 (lef-9) gene encodes a subunit of the virally encoded RNA polymerase specific for the transcription of late and very late genes. This subunit contains 5 of the 7 residues in a conserved motif present in large subunits of other polymerases. In these polymerases, the motif is part of the catalytic center of the enzyme complex. Alteration of this motif in lef-9 revealed that it was necessary for late promoter expression, suggesting that it is a potential catalytic center. Lef-8 also contains a conserved motif that has been shown to be essential in the expression of late and very late genes. We suggest that the catalytic center of the RNA polymerase is formed by different subunits interacting to bring the catalytic motifs in close proximity and in the correct spatial arrangement for proper function. Additionally, there is preliminary evidence that LEF-8 and LEF-9 interact in a related baculovirus, Bombyx mori nucleopolyhedrovirus (BmNPV). Although additional experiments are needed to complete our proposed work, we have optimized conditions for the expression of the desired proteins and we will proceed to test their interaction in AcMNPV.