Structure-function analysis of SWI2/SNF2 enzymes.

Biochemical and structural progress over the last years has revealed that SWI2/SNF2 family chromatin remodeling or DNA repair enzymes are molecular motors that transport duplex DNA along a helicase-like domain using ATP-hydrolysis. The screw motion of DNA along the active site probably generates the force to disrupt chromatin or other protein:DNA complexes. In this chapter, we describe biochemical and structural approaches to study the molecular mechanism of SWI2/SNF2 enzymes. In particular, we describe assays to monitor DNA dependent ATPase activity, translocation on duplex DNA, and DNA distortion activity. We also describe recent progress in the crystallization and structure determination of SWI2/SNF2 enzymes in complex with duplex DNA.