The integrase family of site-specific recombinases catalyze a diverse array of DNA rearrangements in archaebacteria, eubacteria and yeast. The structure of theDNA binding domain of the the conjugative transposon Tn916 integrase protein was determined using NMR spectroscopy. The N-terminal domain was found to be structurally similar to the double stranded RNA binding domain (dsRBD). Experimental evidence suggests that the integrase protein interacts with DNA using residues located on the face of its three stranded beta-sheet [<cite idref="PUB00007416"/>].