The Isc A from Acidithiobacillus ferrooxidans is an iron-sulfur protein which assemble the Fe4S4Cluster with intracellular iron and sulfur
IscA was proposed to be involved in the iron-sulfur cluster assembly in Acidithiobacillus ferrooxidans encoded by the iscSUA operon, but the role of IscA in the iron-sulfur cluster assembly still remains controversial. In this study, the IscA from A. ferrooxidans ATCC 23270 was successfully expressed in Escherichia coli, and purified by affinity chromatography to homogeneity. To our surprise, the purified IscA was observed to be an iron-sulfiir protein according to MALDI-TOF-MS and spectra results, which was capable of recruiting intracellular iron and sulfur and hosted a stable Fe4S4 cluster. Site-directed mutagenesis for the protein revealed that Cys35, Cys99 and CyslOl were in ligating with the Fe4S4 cluster. The Fe4S4 cluster could be assembled in apoIscA with Fe2+ and sulfide in vitro. The IscA from A. ferrooxidans may function as a scaffold protein for the pre-assembly of Fe-S cluster and then transfer it to target proteins in A. ferrooxidans. A model for the structure of IscA was constructed by Insight II software (Accelrys Inc.)
IscA Acidithiobacillus ferrooxidans Expression Purification His-tag Iron-sulfur cluster assembly Molecular modelling.
Jia Zeng Meimei Geng Huidan Jiang Yuandong Liu Jianshe Liu Guanzhou Qiu
From the Department of Bioengineering, School of Resources Processing and Bioengineering, Central South University, Changsha 410083, P. R. China
国际会议
杭州
英文
1421-1452
2007-04-01（万方平台首次上网日期，不代表论文的发表时间）