Mammalian SWI/SNF complexes are evolutionary con-served, ATP-dependent chromatin remodeling units. BAF155 in the SWI/SNF complex contains several highly conser-ved domains, including SANT, SWIRM, and leucine zipper domains. The biological roles of the SWIRM domain re-main unclear; however, both structural and biochemical analyses of this domain have suggested that it could mediate protein-protein or protein-DNA interactions during the chromatin remodeling process. The human BAF155 SWIRM domain was cloned into the Escherichia coli expression vector pMAL-c2X and purified using affinity chro-matography for structural analysis. We report the backbone 1H, 15N, and 13C resonance assignments and secondary structure of this domain using nuclear magnetic resonance (NMR) spectroscopy and the TALOS+ program. The secondary structure consists of five ?-helices that form a typical histone fold for DNA interactions. Our data suggest that the BAF155 SWIRM domain interacts with nucleosome DNA (Kd = 0.47 ?M).

Keywords: BAF155, NMR spectroscopy, protein-DNA interaction, secondary structure, SWIRM domain