Principal Investigator Tania Baker
Mu Transposase: A Member of the Transposase/Integrase Superfamily Transposition of many elements occurs using a common set of DNA cleavage and joining reactions that take place on the two ends of the mobile element's DNA. This similarity in the mechanism is reflected in the proteins that catalyze the reactions. Mu transposase (MuA) carries a core domain containing residues that contribute to the enzyme's active site. This domain is highly conserved among many transposases and the retroviral integrases. We have determined how the conserved catalytic domains are organized in the active tetramer of Mu transposase. These experiments led to two important conclusions: (1) the same catalytic domain donates the active site for both DNA cleavage and the subsequent DNA joining on one end of the genome, and (2) the subunit donating this catalytic domain to one end of the genome is bound to the other DNA end. This interwoven subunit arrangement explains the precision with which recombination occurs using a pair of DNA signals and provides an example of how the architecture of a protein-DNA complex can define the reaction products.