The crystal structure of nucleoplasmin-core: implications for histone binding and nucleosome assembly.
The efficient assembly of histone complexes and nucleosomes requires the participation of molecular chaperones. Currently, there is a paucity of data on their mechanism of action. We now present the structure of an N-terminal domain of nucleoplasmin (Np-core) at 2.3 A resolution. The Np-core monomer is an eight-stranded beta barrel that fits snugly within a stable pentamer. In the crystal, two pentamers associate to form a decamer. We show that both Np and Np-core are competent to assemble large complexes that contain the four core histones. Further experiments and modeling suggest that these complexes each contain five histone octamers which dock to a central Np decamer. This work has important ramifications for models of histone storage, sperm chromatin decondensation, and nucleosome assembly.
Dutta
S
S
Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA.
Akey
I V
IV
Dingwall
C
C
Hartman
K L
KL
Laue
T
T
Nolte
R T
RT
Head
J F
JF
Akey
C W
CW
D000595:Amino Acid Sequence; D000818:Animals; D018360:Crystallography, X-Ray; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry*; D056489:Nucleoplasmins; D009707:Nucleosomes / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry*; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
D006657:Histones; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D056489:Nucleoplasmins; D009707:Nucleosomes; D010750:Phosphoproteins