Dual functions of largest NURF subunit NURF301 in nucleosome sliding and transcription factor interactions

NURF is an ISWI complex of four proteins that uses the energy of ATP hydrol ysis to catalyze nucleosome sliding. Three NURF components have been identi fied previously. We have cloned cDNA encoding the largest NURF subunit, rev ealing a 301 kDa polypeptide (NURF301) that shares structural motifs with A CF1. We have reconstituted full and partial NURF complexes from recombinant proteins and show that NURF301 and the ISWI ATPase are necessary and suffi cient for accurate and efficient nucleosome sliding. An HMGA/HMGI(Y)-like d omain of NURF301 that facilitates nucleosome sliding indicates the importan ce of DNA conformational changes in the sliding mechanism. NURF301 also sho ws interactions with sequence-specific transcription factors, providing a b asis for targeted recruitment of the NURF complex to specific genes.