The copper chelator methanobactin from Methylosinus trichosporium OB3b binds copper(I).
The oxidation state of copper bound to methanobactin, a small siderophore-like molecule from the methanotroph Methylosinus trichosporium OB3b, was investigated. Purified methanobactin loaded with Cu(II) exhibits a weak EPR signal probably due to adventitious Cu(II). The EPR signal intensity increases significantly upon addition of the strong oxidant nitric acid. Features of the X-ray absorption near edge spectrum, including a 1s --> 4p transition at 8985 eV, further indicate the presence of Cu(I). EXAFS data were best fit using a multiple scattering model generated from previously reported crystallographic parameters. These results establish definitively that M. trichosporium OB3b methanobactin binds Cu(I) and suggest that methanobactin itself reduces Cu(II) to Cu(I).
Hakemian
Amanda S
AS
Department of Biochemistry, Northwestern University, Evanston, Illinois 60208, USA.
Tinberg
Christine E
CE
Kondapalli
Kalyan C
KC
Telser
Joshua
J
Hoffman
Brian M
BM
Stemmler
Timothy L
TL
Rosenzweig
Amy C
AC
D015502:Absorptiometry, Photon; D003300:Copper / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism*; D020602:Methylosinus trichosporium / Q000737:chemistry*; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D011485:Protein Binding
D007093:Imidazoles; D009842:Oligopeptides; C491147:methanobactin; D003300:Copper