Dr. Dayie is interested in understanding how RNA forms complexes to regulate gene expression, and much of his work focuses on devising new research methods.

Dr. Dayie, a native of Ghana, received his undergraduate degree from Hamilton College in Upstate New York. He completed a Ph.D. in Biophysics at Harvard and postdoctoral fellowships at MIT and at the Scripps Research Institute. He was an adjunct at Kent State and Case Western Universities (simultaneously!) before joining the faculty at the University of Maryland in 2008.

Although RNA is traditionally thought of only as an intermediate between genes (encoded in DNA) and their protein products, protein-coding genes make up a very small fraction of the human genome. It was thought that the majority of the genome was “junk DNA,” coding for RNAs that didn’t produce any protein and were degraded. Increasingly, however, it is becoming clear that non-coding RNAs themselves can serve important structural and functional roles in the cell. For instance, the spliceosome is composed of several non-coding RNAs bound together with proteins.

In bacteria, some non-coding RNAs act as riboswitches, which are metabolite sensors/regulators. A cell producing some protein product of a gene (a metabolite) needs a mechanism to shut off expression of the gene once concentration of the metabolite gets too high. Riboswitches do that: when the concentration of their metabolite builds up, it will bind to the riboswitch RNA and cause it to change shape. In its metabolite-bound form, the riboswitch blocks the mRNA for the metabolite-producing gene from being translated. Thus, metabolite levels will begin to drop again.

In a recent paper, Dr. Dayie and colleagues investigated a riboswitch called the SAM-II riboswitch, which regulates an essential metabolite (S-adenosyl methionine, SAM). Specifically, they were interested in what happens when magnesium binds to the SAM-II ribsowitch when SAM is not present. Using computer simulations (based on experimental data), they show that magnesium helps to “pre-organize” the riboswitch, pulling it into a more compact conformation. Without this compaction, the two halves of the SAM-binding site are too far apart to stably bind SAM. This research helps to underscore the importance of metal ions in stabilizing riboswitches, which is useful for synthetic biologists, who are attempting to manipulate them to change bacterial gene expression.