Spontaneous assembly of redox-active iron-sulfur clusters at low concentrations of cysteine

Jordan, S.F. and Ioannou, I. and Rammu, H. and Halpern, A. and Bogart, L.K. and Ahn, M. and Vasiliadou, R. and Christodoulou, J. and Maréchal, Amandine and Lane, N. (2021) Spontaneous assembly of redox-active iron-sulfur clusters at low concentrations of cysteine. Nature Communications 12 , p. 5925. ISSN 2041-1723.

Abstract

Iron-sulfur (FeS) proteins are ancient and fundamental to life, being involved in electron transfer and CO2 fixation. FeS clusters have structures similar to the unit-cell of FeS minerals such as greigite, found in hydrothermal systems linked with the origin of life. However, the prebiotic pathway from mineral surfaces to biological clusters is unknown. Here we show that FeS clusters form spontaneously through interactions of inorganic Fe2+/Fe3+ and S2− with micromolar concentrations of the amino acid cysteine in water at alkaline pH. Bicarbonate ions stabilize the clusters and even promote cluster formation alone at concentrations >10 mM, probably through salting-out effects. We demonstrate robust, concentration-dependent formation of [4Fe4S], [2Fe2S] and mononuclear iron clusters using UV-Vis spectroscopy, 57Fe-Mössbauer spectroscopy and 1H-NMR. Cyclic voltammetry shows that the clusters are redox-active. Our findings reveal that the structures responsible for biological electron transfer and CO2 reduction could have formed spontaneously from monomers at the origin of life.

Metadata

Statistics

DownloadsShow export options

Export as XMLJSONCSV

Activity Overview

6 month trend

67Downloads

6 month trend

86Hits

Additional statistics are available via IRStats2.

Archive Staff Only (login required)

Edit/View Item