The crystal structure of FdxA, a 7Fe ferredoxin from Mycobacterium smegmatis
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- 作者：Stefano Ricagno ; Matteo de Rosa ; Aless ; ro Aliverti ; Giuliana Zanetti ; Martino Bolognesi
- 关键词：7Fe ferredoxin ; Mycobacterium smegmatis ; Mycobacterium tuberculosis ; Electron transfer ; [Fe– ; S] cluster ; [4Fe– ; 4S] cluster instability ; Protein structure ; X-ray crystallography
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2007
- 出版时间：17 August 2007
- 年：2007
- 卷：360
- 期：1
- 页码：97-102
- 全文大小：1003 K
文摘
Mycobacterium smegmatis ferredoxin FdxA, which has an orthologue ferredoxin in Mycobacterium tuberculosis, FdxC, contains both one [3Fe–4S] and one [4Fe–4S] cluster. M. smegmatis FdxA has been shown to be a preferred ferredoxin substrate of FprA [F. Fischer, D. Raimondi, A. Aliverti, G. Zanetti, Mycobacterium tuberculosis FprA, a novel bacterial NADPH-ferredoxin reductase, Eur. J. Biochem. 269 (2002) 3005–3013], an adrenodoxin reductase-like flavoprotein of M. tuberculosis, suggesting that M. tuberculosis FdxC could be the physiological partner of the enzyme in providing reducing power to the cytochromes P450. We report here the crystal structure of FdxA at 1.6 Å resolution (Rfactor 16.5 % , Rfree 20.2 % ). Besides providing an insight on protein architecture for this 106-residue ferredoxin, our crystallographic investigation highlights lability of the [4Fe–4S] center, which is shown to loose a Fe atom during crystal growth. Due to their high similarity (87 % sequence identity), the structure here reported can be considered a valuable model for M. tuberculosis FdxC, thus representing a step forward in the study of the complex mycobacterial redox pathways.