Yoda K, Ando S, Okuda A, Kikuchi A, Okazaki T. In vitro assembly of the CENP-B/alpha-satellite DNA/core histone complex: CENP-B causes nucleosome positioning.
Genes Cells 1998;
3:533-48. [PMID:
9797455 DOI:
10.1046/j.1365-2443.1998.00210.x]
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Abstract
BACKGROUND
We have studied the nucleosome structure formed from alpha-satellite DNA bound with CENP-B and core histones, in order to develop a previous proposal that the CENP-B dimer may play a critical role in the assembly of higher order structures of the human centromere by juxtaposing CENP-B boxes in long alpha-satellite arrays.
RESULTS
The dimeric structure of CENP-B was sufficiently stable to bundle together two 3.5 kbp DNA fragments when each DNA contained a CENP-B box. When the same length of DNA included two CENP-B boxes, the intra-molecular interaction with the CENP-B dimer predominated, resulting in the formation of loop structures. The in vitro assembly of CENP-B/alpha-satellite DNA/core histone complexes with the aid of nucleosome assembly protein-1 (NAP-1) permitted an investigation into the nucleosome arrangement in alpha-satellite DNA with CENP-B bound to CENP-B boxes. Footprint analyses with micrococcal nuclease (MNase) revealed that CENP-B causes nucleosome positioning between pairs of CENP-B boxes with unique hypersensitive sites created on both sides.
CONCLUSION
We propose that CENP-B functions as a structural factor in the centromere region in order to establish a unique, centromere specific pattern of nucleosome positioning.
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