G. Schnitzler et al., HUMAN SWI SNF INTERCONVERTS A NUCLEOSOME BETWEEN ITS BASE STATE AND ASTABLE REMODELED STATE/, Cell (Cambridge), 94(1), 1998, pp. 17-27
The human SWI/SNF complex remodels nucleosome structure in an ATP-depe
ndent manner, although the nature of this change has not been determin
ed. Here we show that hSWI/SNF and ATP generate an altered nucleosomal
structure that is stable in the absence of SWI/SNF. This product has
an altered sensitivity to digestion by DNAse, restriction enzymes, and
micrococcal nuclease, and an increased affinity for GAL4. It has the
same protein composition but is approximately twice the size of a norm
al nucleosome. Incubation of the altered nucleosome with hSWI/SNF conv
erts this structure back to a standard nucleosome in an ATP-dependent
process. These results suggest that hSWI/SNF acts by facilitating an e
xchange between normal and altered, more accessible, nucleosome confor
mations.