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.
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.
Authors: Kristina M Smith; Jonathan M Galazka; Pallavi A Phatale; Lanelle R Connolly; Michael Freitag Journal: Chromosome Res Date: 2012-07 Impact factor: 5.239
Authors: Y Tanaka; O Nureki; H Kurumizaka; S Fukai; S Kawaguchi; M Ikuta; J Iwahara; T Okazaki; S Yokoyama Journal: EMBO J Date: 2001-12-03 Impact factor: 11.598
Authors: Kristin A Maloney; Lori L Sullivan; Justyne E Matheny; Erin D Strome; Stephanie L Merrett; Alyssa Ferris; Beth A Sullivan Journal: Proc Natl Acad Sci U S A Date: 2012-07-30 Impact factor: 11.205