[ PDB file ] [ PubMed link ]
The THAP (Thanatos-associated protein) domain is a recently discovered zinc-binding domain found in proteins involved in transcriptional regulation, cell-cycle control, apoptosis and chromatin modification. It contains a single zinc atom ligated by cysteine and histidine residues within a Cys-X(2-4)-Cys-X(35-53)-Cys-X(2)-His consensus. We determined the NMR solution structure of the THAP domain from Caenorhabditis elegans C-terminal binding protein (CtBP) and show that it adopts a fold containing a treble clef motif, with some similarity to the zinc finger-associated domain (ZAD) from Drosophila Grauzone. We have also shown using gel-shift data that CtBP-THAP is able to bind DNA. Other THAP domains have been reported to be involved in mediating protein interactions, suggesting that THAP domains might exhibit a functional diversity similar to that observed for classical and GATA-type zinc fingers.