The THAP domain: a novel protein motif with similarity to the DNA-binding domain of P element transposase

Abstract

We have identified a novel evolutionarily conserved protein motif – designated the THAP domain – that defines a new family of cellular factors. We have found that the THAP domain presents striking similarities with the site-specific DNA-binding domain (DBD) of Drosophila P element transposase, including a similar size, N-terminal location, and conservation of the residues that define the THAP motif, such as the C2CH signature (Cys-Xaa 2–4-Cys-Xaa 35–50-Cys-Xaa 2-His). Our results suggest that the THAP domain is a novel example of a DBD that is shared between cellular proteins and transposases from mobile genomic parasites.