Methanobactin, a Copper-Acquisition Compound from Methane-Oxidizing Bacteria
2004; American Association for the Advancement of Science; Volume: 305; Issue: 5690 Linguagem: Inglês
10.1126/science.1098322
ISSN1095-9203
AutoresHyung J. Kim, David W. Graham, Alan A. DiSpirito, Michail A. Alterman, Nadezhda A. Galeva, Cynthia K. Larive, D. J. Asunskis, Peter M. A. Sherwood,
Tópico(s)Metal-Catalyzed Oxygenation Mechanisms
ResumoSiderophores are extracellular iron-binding compounds that mediate iron transport into many cells. We present evidence of analogous molecules for copper transport from methane-oxidizing bacteria, represented here by a small fluorescent chromopeptide (C45N12O14H62Cu, 1216 daltons) produced by Methylosinus trichosporium OB3b. The crystal structure of this compound, methanobactin, was resolved to 1.15 angstroms. It is composed of a tetrapeptide, a tripeptide, and several unusual moieties, including two 4-thionyl-5-hydroxy-imidazole chromophores that coordinate the copper, a pyrrolidine that confers a bend in the overall chain, and an amino-terminal isopropylester group. The copper coordination environment includes a dual nitrogen- and sulfur-donating system derived from the thionyl imidazolate moieties. Structural elucidation of this molecule has broad implications in terms of organo-copper chemistry, biological methane oxidation, and global carbon cycling.
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