Crystal structure of the human centromere protein B (CENP-B) dimerization domain at 1.65-A resolution.
The human centromere protein B (CENP-B), a centromeric heterochromatin component, forms a homodimer that specifically binds to a distinct DNA sequence (the CENP-B box), which appears within every other alpha-satellite repeat. Previously, we determined the structure of the human CENP-B DNA-binding domain, CENP-B-(1-129), complexed with the CENP-B box DNA. In the present study, we determined the crystal structure of its dimerization domain (CENP-B-(540-599)), another functional domain of CENP-B, at 1.65-A resolution. CENP-B-(540-599) contains two alpha-helices, which are folded into an antiparallel configuration. The CENP-B-(540-599) dimer formed a symmetrical, antiparallel, four-helix bundle structure with a large hydrophobic patch in which 23 residues of one monomer form van der Waals contacts with the other monomer. In the CENP-B-(540-599) dimer, the N-terminal ends of CENP-B-(540-599) are oriented on opposite sides of the dimer. This CENP-B dimer configuration may be suitable for capturing two distant CENP-B boxes during centromeric heterochromatin formation.
Tawaramoto
Maki S
MS
RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
Park
Sam-Yong
SY
Tanaka
Yoshinori
Y
Nureki
Osamu
O
Kurumizaka
Hitoshi
H
Yokoyama
Shigeyuki
S
D000595:Amino Acid Sequence; D001324:Autoantigens; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins; D019281:Dimerization; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
D001324:Autoantigens; C497926:CENPB protein, human; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins