A dityrosyl-diiron radical cofactor center is essential for human ribonucleotide reductases

Bingsen Zhou, Jimin Shao, Leila Su, Yate Ching Yuan, Christina Qi, Jennifer Shih, Bixin Xi, Bernard Chu, Yun Yen

研究成果: 雜誌貢獻文章同行評審

15 引文 斯高帕斯(Scopus)


Ribonucleotide reductase catalyzes the reduction of ribonucleotides to deoxyribonucleotides for DNA biosynthesis. A tyrosine residue in the small subunit of class I ribonucleotide reductase harbors a stable radical, which plays a central role in the catalysis process. We have discovered that an additional tyrosine residue, conserved in human small subunits hRRM2 and p53R2, is required for the radical formation and enzyme activity. Mutations of this newly identified tyrosine residue obliterated the stable radical and the enzymatic activity of human ribonucleotide reductases shown by electron paramagnetic resonance spectroscopy and enzyme activity assays. Three-dimensional structural analysis reveals for the first time that these two tyrosines are located at opposite sides of the diiron cluster. We conclude that both tyrosines are necessary in maintaining the diiron cluster of the enzymes, suggesting that the assembly of a dityrosyl-diiron radical cofactor center in human ribonucleotide reductases is essential for enzyme catalytic activity. These results should provide insights to design better ribonucleotide reductase inhibitors for cancer therapy.

頁(從 - 到)1830-1836
期刊Molecular Cancer Therapeutics
出版狀態已發佈 - 12月 2005

ASJC Scopus subject areas

  • 腫瘤科
  • 癌症研究


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