Regulation of ISW2 by concerted action of histone H4 tail and extranucleosomal DNA.
The stable contact of ISW2 with nucleosomal DNA approximately 20 bp from the dyad was shown by DNA footprinting and photoaffinity labeling using recombinant histone octamers to require the histone H4 N-terminal tail. Efficient ISW2 remodeling also required the H4 N-terminal tail, although the lack of the H4 tail can be mostly compensated for by increasing the incubation time or concentration of ISW2. Similarly, the length of extranucleosomal DNA affected the stable contact of ISW2 with this same internal nucleosomal site, with the optimal length being 70 to 85 bp. These data indicate the histone H4 tail, in concert with a favorable length of extranucleosomal DNA, recruits and properly orients ISW2 onto the nucleosome for efficient nucleosome remodeling. One consequence of this property of ISW2 is likely its previously observed nucleosome spacing activity.
Dang
Weiwei
W
Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, 1245 Lincoln Dr., Neckers Bldg., Room 229, Carbondale, IL 62901-4413, USA.
Kagalwala
Mohamedi N
MN
Bartholomew
Blaine
B
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000235:genetics*; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004271:DNA, Fungal; D006657:Histones; C086468:ISWI protein; D009707:Nucleosomes; D014157:Transcription Factors; D000251:Adenosine Triphosphatases