Pol n? The chromatin remodeler changes the local structure of chromatin, allowing binding of factors to their sites previously occluded by nucleosomes The remodeling may cause nucleosome loss, or transient exposure of previously obscured DNA sequences 2005-10-29 Chaoqun Wu, Fudan University
2005-10-29 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 16 • The chromatin remodeler changes the local structure of chromatin, allowing binding of factors to their sites previously occluded by nucleosomes • The remodeling may cause nucleosome loss, or transient exposure of previously obscured DNA sequences Pol II Ac Ac Ac Ac TFIIBTFIID Ac Ac Ac Ac
Next to remodeling UThe chromatin remodeler changes the local structure of chromatin, allowing binding of factors to their sites previously occluded by nucleosomes UThe remodeling may cause nucleosome loss, or transient exposure of previously obscured dNA sequences 2005-10-29 Chaoqun Wu, Fudan University
2005-10-29 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 17 Next to remodeling The chromatin remodeler changes the local structure of chromatin, allowing binding of factors to their sites previously occluded by nucleosomes The remodeling may cause nucleosome loss, or transient exposure of previously obscured DNA sequences
A simplified version of the events that lead from a silent to an actively transcribing from chromatin. In this version, a remodelling complex, guided by a pioneer factor, associates with the silent chromatin The remodeling complex changes the chromatin structure -for example, through associated ATPases, leading to nucleosome displacement, or through associated histone acetyltransferases (HATs)that modify the histones locally 2005-10-29 Chaoqun Wu, Fudan University
2005-10-29 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 18 A simplified version of the events that lead from a silent to an actively transcribing from chromatin. In this version, a remodelling complex, guided by a pioneer factor, associates with the silent chromatin. The remodeling complex changes the chromatin structure — for example, through associated ATPases, leading to nucleosome displacement, or through associated histone acetyltransferases (HATs) that modify the histones locally
How does a chromatin Twist defect diffusion remodeler function 、L Nucleosome osltionir Bulge diffu Nucleosomal dna site ex DNA unwrapping Dimer los Dimer loss +Z 1\ Altered histol Ito a) Twist (b)Writhe exchange 2005-10-29 Chaoqun Wu, Fudan University
2005-10-29 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 19 How does a chromatin remodeler function?
gnginignjimi n Mechanism of ATP-dependent Chromatin Remodeling Complex (A)complex binding A)Binding of remodeling complexes to DNA and nucleosomes ATP (B)"k onsen g of the chromatin structur (B)ATP-dependent nucleosome disruption (C)Chromatin remodeling TWo-step model of SWI/SNF and (C)remodeling RSC action in chromatin remodeling The binding of the remodeling 0负 mplex to chromatin iS ATP octamer transfer octamer sliding 2005-10-29 Chaoqun Wu, Fudan University
2005-10-29 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 20 Mechanism of ATP-dependent Chromatin Remodeling Complex Two-step model of SWI/SNF and RSC action in chromatin remodeling. The binding of the remodeling complex to chromatin is ATP independent (A) Binding of remodeling complexes to DNA and nucleosomes. (B) ATP-dependent nucleosome disruption. (C) Chromatin remodeling