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The SUF iron–sulfur cluster biosynthetic machinery: Sulfur transfer from the SUFS–SUFE complex to SUFA
Author(s) -
Sendra Maïté,
Ollagnier de Choudens Sandrine,
Lascoux David,
Sanakis Yiannis,
Fontecave Marc
Publication year - 2007
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2007.02.058
Subject(s) - iron–sulfur cluster , chemistry , sulfur , cysteine , escherichia coli , biochemistry , ferrous , scaffold protein , covalent bond , metalloprotein , crystallography , gene , enzyme , organic chemistry , signal transduction
Iron–sulfur cluster biosynthesis depends on protein machineries, such as the ISC and SUF systems. The reaction is proposed to imply binding of sulfur and iron atoms and assembly of the cluster within a scaffold protein followed by transfer of the cluster to recipient apoproteins. The SufA protein from Escherichia coli , used here as a model scaffold protein is competent for binding sulfur atoms provided by the SufS–SufE cysteine desulfurase system covalently as shown by mass spectrometry. Investigation of site‐directed mutants and peptide mapping experiments performed on digested sulfurated SufA demonstrate that binding exclusively occurs at the three conserved cysteines (cys50, cys114, cys116). In contrast, it binds iron only weakly ( K a = 5 × 10 5 M −1 ) and not specifically to the conserved cysteines as shown by Mössbauer spectroscopy. [Fe–S] clusters, characterized by Mössbauer spectroscopy, can be assembled during reaction of sulfurated SufA with ferrous iron in the presence of a source of electrons.