Calcium binding to HMG1 protein induces DNA looping by the HMG‐box domains

FEBS Letters

Reich, Josef¹  S̆tros, Michal¹  Kolíbalová, Anna¹ 

[1] Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic

关键词: DNA looping;    DNA compaction;    HMG1;    HMG box;    Calcium;    Electron microscopy;    FPLC;    fast protein liquid chromatography;    EM;    electron microscopy;    HMG;    high mobility group;    NEM;    N-ethylmaleimide;    PMSF;    phenylmethylsulfonyl fluoride;   

DOI  :  10.1016/0014-5793(94)00364-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Electron microscopy has shown that non-histone chromosomal HMG1 could induce DNA looping or compaction in the presence (but not in the absence) of Ca²⁺. The effect of calcium on DNA looping and compaction was interpreted as calcium binding to the acidic C-domain of HMG1. Both individual DNA-binding HMG1-box domains A and B were found to be involved in DNA looping and compaction. Treatment of HMG1 with a thiol-specific reagent, N-ethylmaleimide, inhibited the ability of the protein to induce DNA looping and compaction but not the electrostatic interaction with DNA. These results indicated that cysteine-sulfhydryl groups of the HMG1-box domains A and B are specifically involved in DNA looping and compaction, and that in the absence of calcium the acidic C-domain down-regulates these effects by modulation of the DNA-binding properties of the HMG1-box domains.

【 授权许可】

Unknown