Structural determinants for generating centromeric chromatin.
Mammalian centromeres are not defined by a consensus DNA sequence. In all eukaryotes a hallmark of functional centromeres--both normal ones and those formed aberrantly at atypical loci--is the accumulation of centromere protein A (CENP-A), a histone variant that replaces H3 in centromeric nucleosomes. Here we show using deuterium exchange/mass spectrometry coupled with hydrodynamic measures that CENP-A and histone H4 form sub-nucleosomal tetramers that are more compact and conformationally more rigid than the corresponding tetramers of histones H3 and H4. Substitution into histone H3 of the domain of CENP-A responsible for compaction is sufficient to direct it to centromeres. Thus, the centromere-targeting domain of CENP-A confers a unique structural rigidity to the nucleosomes into which it assembles, and is likely to have a role in maintaining centromere identity.
Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093, USA.
Ben E
BE
Black
Daniel R
DR
Foltz
Srinivas
S
Chakravarthy
Karolin
K
Luger
Virgil L
VL
Woods
Don W
DW
Cleveland
D000595:Amino Acid Sequence; D001324:Autoantigens / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D045744:Cell Line, Tumor; D002503:Centromere / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000076247:Centromere Protein A; D002843:Chromatin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000378:metabolism*; D041961:Deuterium Exchange Measurement; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
D001324:Autoantigens; C000619700:CENPA protein, human; D000076247:Centromere Protein A; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009707:Nucleosomes