A grant is awarded to Iowa State University for research into the evolution of bacterial operons. Many bacterial proteins work together in the same metabolic pathway, and/or as a complex. In many cases, the genes coding for these proteins are clustered together on the chromosome are under a common controlling mechanism, and are transcribed into a single RNA molecule from which the proteins are translated. It is estimated that, depending on the individual genome, between 5 and 25% of bacterial genes reside in operons. Work will explore whether the construction and/or destruction of clusters of co-transcribed genes takes place as a sequential series of events that can be identified. This research will identify the events that happen in operon evolution through comparative genome analyses of a large number of bacterial genomes. These events include gene gain, gene loss, lateral gene transfer, and different types of changes in the genomic structure. The questions which will be answered are: which are the determining events of operon evolution? Are there events that are more and less dominant in defining a change over time in operons? Are these events universal, or vary between operons and different bacterial genera? If the latter, which are the varying dominant events and what can we learn about operon evolution from studying them?
The ability to simultaneously control the transcription of related genes is a strong genetic mechanism that influences bacterial life and functionality on many levels. Understanding how operons evolve will provide insight into one of the most basic and prevalent bacterial genetic structures. This, in turn, will help us better understand the evolution bacteria, which constitute the most diverse and influential of life's domains. This study enables the introduction of new hypotheses to understanding how operons evolve, and proposes that different operons may have evolved using different mechanisms that can be identified. This project, at the interface of computational science and biology, will train undergraduate and graduate students, including programs that support minority education and research. The result of this project will be disseminated through a freely-accessible database describing operons and their evolutionary trajectories.
