Iron-binding activity of human iron-sulfur cluster assembly protein hIscA1.
Iron-binding activity of human iron-sulfur cluster assembly protein hIscA1.
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DOI：
10.1042/bj20100122
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发表时间：
2010-04-28
期刊：
影响因子：
--
通讯作者：
Ding H
中科院分区：
文献类型：
--
作者：
Lu J;Bitoun JP;Tan G;Wang W;Min W;Ding H
铁-硫簇组装蛋白ISCA的人类同源物(HIscA1)已被克隆并在大肠杆菌细胞中表达。紫外-可见吸收光谱和电子顺磁共振(EPR)测量表明，从大肠杆菌细胞中纯化的hIscA1含有一个单核铁中心，在大肠杆菌中表达的hIscA1中的铁结合可以进一步受到细胞生长介质中铁含量的调节。进一步的研究表明，纯化的hIscA1与铁结合，铁结合常数约为。2.0×1019M−1，铁结合的hIscA1能够为拟议的大肠杆菌支架蛋白IscU中的铁-硫簇组装提供铁。互补实验表明，在好氧条件下，hIscA1可以部分替代ISCA在M9微量培养基中恢复大肠杆菌的生长。这些结果表明，人类IscA1和大肠杆菌IscA一样，是一种铁结合蛋白，可能作为铁-硫簇生物发生的铁伴侣。
A human homologue of the iron-sulfur cluster assembly protein IscA (hIscA1) has been cloned and expressed in Escherichia coli cells. The UV-visible absorption and EPR (electron paramagnetic resonance) measurements reveal that hIscA1 purified from E. coli cells contains a mononuclear iron center and that the iron binding in hIscA1 expressed in E. coli cells can be further modulated by the iron content in the cell growth medium. Additional studies show that purified hIscA1 binds iron with an iron association constant of approx. 2.0 × 1019 M−1, and that the iron-bound hIscA1 is able to provide the iron for the iron-sulfur cluster assembly in a proposed scaffold protein IscU of E. coli in vitro. The complementation experiments indicate that hIscA1 can partially substitute for IscA in restoring the cell growth of E. coli in the M9 minimal medium under aerobic conditions. The results suggest that human IscA1, like E. coli IscA, is an iron binding protein that may act as an iron chaperone for biogenesis of iron-sulfur clusters.