Transition protein 4 from boar late spermatid nuclei is a topological factor that stimulates DNA‐relaxing activity of topoisomerase I

FEBS Letters

Sato, Hiroki¹  Akama, Kuniko¹  Kondo, Miyuki¹  Nakano, Minoru¹ 

[1] Graduate School of Science and Technology, Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba 263-8522, Japan

关键词: Transition protein;    Topoisomerase;    Spermatid nucleus;    TP;    transition protein;    BSA;    bovine serum albumin;    SDS;    sodium dodecyl sulfate;   

DOI  :  10.1016/S0014-5793(98)01649-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Transition protein 4 (TP4) from boar late spermatid nuclei, having higher affinity for double-stranded DNA and a local melting activity of DNA, stimulated SV40 DNA-relaxing activity of eukaryotic topoisomerase I at TP4/DNA molar ratios of 6.6–11. A TP4-spermidine mixture stimulated the activity of topoisomerase I much more than spermidine alone, but no more than TP4 alone, and poly-l-arginine did not. These results suggest that TP4 contributes to the chromatin reorganization in the late spermatid nuclei from nucleosomal-type structure with negatively supercoiled DNA to nucleoprotamine structure with no supercoiled DNA.

【 授权许可】

Unknown