The ITR binding domain of the mariner Mos-1 transposase

Mariner-like elements are widespread eukaryotic transposons, but Mos-1 is t he only natural element that is known to be active. Little is known about t he biochemistry of mariner transposition. The first step in the process is the binding of the transposase to the 5 ' and 3 ' inverted terminal repeats (ITRs) of the element. Using the 3 ' ITR of the element, we have determine d the binding properties of a recombinant Mos-1 transposase produced in bac teria, and we have used deletion derivatives to localize the minimal ITR bi nding domain between amino acids 1 and 141. Its features and structure indi cate that it differs from the ITR binding domain of the transposase encoded by Tc1-related elements.