| For the past five years, I have been studying the monocot infecting-RNA virus, brome mosaic virus (BMV). RNA viruses are the causative agents of many diseases in plants and animals. While the replication of RNA is an essential step in the pathogenesis of these viruses, we have only a minimal understanding of how RNA replication occurs. This is because few enzyme complexes that direct the replication of RNA viruses have been purified and biochemically characterized. My research involves studying the architecture of the BMV viral replicase. More specifically, I have studied protein-protein interactions between the two BMV viral replication proteins, called 1a and 2a, which contain putative capping/helicase and polymerase functions, respectively. My overall goal was to begin to understand how the BMV RNA synthesis machine is put together.; The main tool that I have used in these studies is the yeast two-hybrid system. Using this tool, I have more fully characterized a previously defined interaction between the 1a and 2a proteins and discovered and characterized novel inter- and intra-molecular interactions within the 1a protein. These results allowed me to develop a working model that explains how and possibly in what order these two proteins assemble to form a replicase complex.; Using computer assisted analysis, I have also generated secondary structure predictions of the 1a capping/methyltransferase-like and 2a polymerase-like proteins. Comparisons of these predicted structures with the known structures of related proteins has provided much information regarding the location of many functional amino acids. This information along with an understanding how the two viral proteins interact offers a basic picture of the replicase machine that will be invaluable to the functional characterization of plant viral RNA replicase proteins. |
