Conformational changes associated with template commitment in ATP-dependent chromatin remodeling by ISW2.
Distinct stages in ATP-dependent chromatin remodeling are found as ISW2, an ISWI-type complex, forms a stable and processive complex with nucleosomes upon hydrolysis of ATP. There are two conformational changes of the ISW2-nucleosome complex associated with binding and hydrolysis of ATP. The initial binding of ISW2 to extranucleosomal DNA, to the entry site, and near the dyad axis of the nucleosome is enhanced by ATP binding, whereas subsequent ATP hydrolysis is required for template commitment and causes ISW2 to expand its interactions with nucleosomal DNA to an entire gyre of the nucleosome and a short approximately 3-4 bp site on the other gyre. The histone-fold-like subunit Dpb4 associates with nucleosomal DNA approximately 15 bp from the ATPase domain as part of this change and may help to disrupt histone-DNA interactions. These additional contacts are independent of the ATPase domain tracking along nucleosomal DNA and are maintained as ISW2 moves nucleosomes on DNA.
Gangaraju
Vamsi K
VK
Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901-4413, USA.
Prasad
Punit
P
Srour
Ali
A
Kagalwala
Mohamedi N
MN
Bartholomew
Blaine
B
D000244:Adenosine Diphosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D042002:Chromatin Assembly and Disassembly; D004257:DNA Polymerase II / Q000378:metabolism; D004271:DNA, Fungal / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006868:Hydrolysis; D008954:Models, Biological; D009707:Nucleosomes / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D004271:DNA, Fungal; D006657:Histones; C086468:ISWI protein; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D004257:DNA Polymerase II; D000251:Adenosine Triphosphatases