Professor Franzen's research is directed toward the elucidation of the structure and the mechanism of action of the mitochondrial and chloroplast self-splicing introns known as the Group II introns.
The current efforts of the laboratory focus on identifying the sequence of nucleotides in the downstream exon which affect various aspects of splicing activity. These exon effector actions include: increasing the rate of the rate-determining initial step of splicing, directing the splicing reaction to occur along the path of forming a branched intermediate, shifting the equilibrium of the second splicing step to favor the forward reaction direction, and protecting the 2'-5' phosphodiester linkage of the intermediate lariat branchpoint nucleotide from hydrolysis. These investigations are part of the collaborative efforts of Drs. Franzen and Peebles.