Young-Jun Park and Karolin Lugerâ€
Department of Biochemistry and molecular Biology, Colorado State University, Fort Collins, CO 80523-1870 Edited by Roger D. Kornberg, Stanford University School of Medicine, Stanford, CA, and approved November 29, 2005 (received for review September 14, 2005)
Nucleosome assembly protein 1 (NAP-1) is an integral component in the establishment, maintenance, and dynamics of eucaryotic chromatin granule. It shuttles histones into the nucleus, assembles nucleosomes, and promotes chromatin ?uidity, thereby affecting the transcription of many genes. The 3.0 Ã… crystal structure of yeast NAP-1 reveals a previously uncharacterized fold with implications for histone binding and shuttling. A long -helix is responsible for homodimerization via a previously uncharacterized antiparallel non-coiled-coil, and an demesne is implicated in proteinprotein interaction. A nuclear export place that is embedded in the dimerization helix is almost completely disguise by an accessory domain that contains several tar unhorse sites for casein kinase II. The four-stranded antiparallel -sheet that characterizes the domain is found in all histone chaperones, despite the absence of homology in sequence, structural context, or quaternary structure.
To our knowledge, this is the ?rst structure of a member of the large NAP family of proteins and suggests a instrument by which the shuttling of histones to and from the nucleus is regulated.
chromatin histone chaperone nuclear enthrall x-ray crystallography
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hromatin assembly and disassembly are dynamic biologic processes that increase chromatin fluidity and regulate the accessibility of the eukaryotic genome to DNA replication, transcription, repair, and cell cycle progression. The basic structural unit of measurement of eukaryotic chromatin is the nucleosome in which 146 bp of DNA are wrap up around a histone octamer that consists of two molecules each of the histones H2A, H2B, H3,...If you want to get a full essay, order it on our website: Orderessay
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