- Ph.D., Massachusetts Institute of Technology, 1990
- B.Sc., McGill University, 1983
Our goal is to understand the process of DNA transposition by crystallizing specific Hermes-DNA complexes at various stages of the transposition reaction. We hope that by understanding how the Hermes protein catalyzes DNA breakage and re-joining reactions, we will gain insights into its mechanism and regulation, allowing us to optimize Hermes (and perhaps other eukaryotic transposases) for use as a genetic tool in eukaryotic cells.
The basic research we are performing is aimed at understanding the various biochemical mechanisms by which discrete pieces of DNA move from one place in the genome to another. This process is called DNA transposition. In particular, we have been studying the eukaryotic transposon, Hermes, an active hAT transposon originally isolated from Musca domestica (the housefly).
We have obtained the crystal structure of the protein alone, in complex with its transposon ends, and are extending this work to the characterization of other steps in the transposition reaction.
Applying Our Research
We are interested in eukaryotic transposons, as they provide a valuable experimental tool to manipulate the genomes of eukaryotic cells. For example, they have been used as a way to eliminate genes selectively and to then observe the consequences. Alternatively, the introduction of specific genes is the conceptual foundation of gene therapy approaches to curing diseases. DNA transposition systems in current use in mammalian cells include the resurrected Sleeping Beauty transposon and piggyBac, which are not always ideal for their desired applications. We reasoned that x-ray structures of eukaryotic DNA transposases would provide important insights into their mechanisms and regulation.
- Structural insights into the mechanism of double strand break formation by Hermes, a hAT family eukaryotic DNA transposase.
- Hickman AB, Voth AR, Ewis H, Li X, Craig NL, Dyda F.
- Nucleic Acids Res (2018 Nov 2) 46:10286-10301. Abstract/Full Text
- Targeting IS608 transposon integration to highly specific sequences by structure-based transposon engineering.
- Morero NR, Zuliani C, Kumar B, Bebel A, Okamoto S, Guynet C, Hickman AB, Chandler M, Dyda F, Barabas O.
- Nucleic Acids Res (2018 May 4) 46:4152-4163. Abstract/Full Text
Research in Plain Language
Essentially all organisms harbor enzymes (proteins) that are able to move discrete segments of DNA from one genomic location to another. Their presence provides a way for organisms to respond to environmental changes, and they have been shown to be major drivers of genome evolution. Interestingly, one of these protein systems appears to have been used by higher organisms to shuffle pieces of DNA in order to generate antibodies. We would like to understand how these proteins work. Our main approach has been to use a method of determining three-dimensional structure, known as x-ray crystallography, as a way to visualize these proteins as they interact with DNA.