A dynamic structural unit of phase-separated heterochromatin protein 1α as revealed by integrative structural analyses

Furukawa A, Yonezawa K, Negami T, Yoshimura Y, Hayashi A, Nakayama J, Adachi N, Senda T, Shimizu K, Terada T, Shimizu N, Nishimura Y, Nucleic Acids Research 53(6) (2025) DOI

SASDU63 – Heterochromatin protein HP1α, delta CSD mutant, in 50 mM NaCl

Heterochromatin protein HP1α, delta CSD mutant
MWI(0) 24 kDa
MWexpected 13 kDa
VPorod 23 nm3
log I(s) 2.10×10-2 2.10×10-3 2.10×10-4 2.10×10-5
Heterochromatin protein HP1α, delta CSD mutant small angle scattering data  s, nm-1
ln I(s)
Heterochromatin protein HP1α, delta CSD mutant Guinier plot ln 2.11×10-2 Rg: 2.8 nm 0 (2.8 nm)-2 s2
(sRg)2I(s)/I(0)
Heterochromatin protein HP1α, delta CSD mutant Kratky plot 1.104 0 3 sRg
p(r)
Heterochromatin protein HP1α, delta CSD mutant pair distance distribution function Rg: 3.0 nm 0 Dmax: 13 nm

Data validation


There are no models related to this curve.

Synchrotron SAXS data from solutions of heterochromatin protein HP1α, delta CSD mutant, in 50 mM NaCl in 20 mM sodium phosphate, 50 mM NaCl, 1 mM DTT, pH 7 were collected on the BL-15A2 beam line at the Photon Factory (PF), High Energy Accelerator Research Organization (KEK; Tsukuba, Japan) using a Pilatus3 2M detector at a sample-detector distance of 1.7 m and at a wavelength of λ = 0.1 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 50.00 μl sample at 4.0 mg/ml was injected onto a Cytiva Superdex 200 Increase 3.2/300 column at 20°C. The flow rate was set to 0.01 mL/min around the peak region. 1800 successive 3 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

SEC-SAXS experiment was performed using an HPLC system, Nexera-i (SHIMADZU). SEC-MALS experiments were performed before the SEC-SAXS experiments and the molecular weight was estimated to be 16.3 kDa.

Heterochromatin protein HP1α, delta CSD mutant (ΔCSD)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   13.3 kDa
Sequence   FASTA