|2kzu, 25 NMR models ()|
|Gene:||DAXX, DADB-159G18.9-007, DAMC-227D19.15-007, DAQB-126H3.2-007, XXbac-BCX165D10.3-007, XXbac-BPG185D15.6-007 (Homo sapiens), RASSF1, hCG_17462 (Homo sapiens)|
DAXX helical bundle (DHB) domain / Rassf1C complex
DAXX is a scaffold protein with diverse roles including transcription and cell cycle regulation. Using NMR spectroscopy, we demonstrate that the C-terminal half of DAXX is intrinsically disordered, whereas a folded domain is present near its N terminus. This domain forms a left-handed four-helix bundle (H1, H2, H4, H5). However, due to a crossover helix (H3), this topology differs from that of the Sin3 PAH domain, which to date has been used as a model for DAXX. The N-terminal residues of the tumor suppressor Rassf1C fold into an amphipathic alpha helix upon binding this DAXX domain via a shallow cleft along the flexible helices H2 and H5 (K(D) approximately 60 muM). Based on a proposed DAXX recognition motif as hydrophobic residues preceded by negatively charged groups, we found that peptide models of p53 and Mdm2 also bound the helical bundle. These data provide a structural foundation for understanding the diverse functions of DAXX.
Structural Characterization of the DAXX N-Terminal Helical Bundle Domain and Its Complex with Rassf1C., Escobar-Cabrera E, Lau DK, Giovinazzi S, Ishov AM, McIntosh LP, Structure. 2010 Dec 8;18(12):1642-53. PMID:21134643
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.