Models for chromatin remodeling: a critical comparison.
Nucleosome remodeling has been shown, in many cases, to involve cis displacement of nucleosomes on the DNA. This process seems similar to the long-recognized random diffusion of nucleosomes along DNA, but the remodeling process is unidirectional and ATP dependent. Several years ago, we developed a model for nucleosome migration, based on the diffusion of "twist-defects" within the nucleosomal DNA. This has been modified into a model that incorporates ATP-dependent defect generation, and can account for many observations concerning remodeling. However, certain experimental studies in recent years have cast doubt on the applicability of the twist-diffusion model for remodeling, and seem to favor instead a "reptation" model. We discuss herein these problems and propose a resolution.
van Holde
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Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
Yager
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D000255:Adenosine Triphosphate / Q000378:metabolism; D001665:Binding Sites; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000378:metabolism
D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D000255:Adenosine Triphosphate; D004247:DNA