@article{9f957d6432994441b6cfb9a47eab3c37,
title = "Evidence for the existence of [2Fe-2S] as well as [4Fe-4S] clusters among FA, FB and FX. Implications for the structure of the Photosystem I reaction center",
abstract = "Core extrusion of the bound iron-sulfur centers from spinach Photosystem I showed the presence of [2Fe-2S] clusters as well as [4Fe-4S] clusters among FA, FB and FX. Extrusion of the iron-sulfur ensemble was not quantitative; however, the presence of [2Fe-2S] clusters correlated with higher concentration of unfolding solvent. Since FX is highly resistant to denaturation, and since FA and FB are known to contain [4Fe-4S] clusters, the [2Fe-2S] clusters are assigned to FX. The presence of [2Fe-2S] clusters in Photosystem I has significance in the structure and organization of FX on the reaction center. Since four cysteinyl ligands are assumed to hold an iron-sulfur cluster, a Photosystem I subunit may consist of two approx. 64-kDa proteins bridged by a single [2Fe-2S] cluster. The complete reaction center would consist of two subunits positioned so that two [2Fe-2S] clusters are in magnetic interaction, thereby constituting FX.",
author = "Golbeck, \{John H.\} and McDermott, \{Ann E.\} and Jones, \{Wayne K.\} and Kurtz, \{D. M.\}",
note = "Funding Information: steines to hold two iron-sulfur clusters; a dimeric arrangement of one PS I-A1 and one PS I-A2 peptide would not. An interaction of two iron-sulfur clusters has been postulated to explain some of the unusual properties exhibited by F x \textbackslash{}[27\textbackslash{}]. For example, the low gay value of 1.91, the extremely broad ESR resonances, and the low redox potential are highly unusual for a \textbackslash{}[4Fe-4S\textbackslash{}]c luster \textbackslash{}[see Ref. 25\textbackslash{}]. Moreover, the ESR microwave power saturation characteristics have indicated that F x cannot be a typical \textbackslash{}[2Fe-2S\textbackslash{}]o r \textbackslash{}[4Fe-4S\textbackslash{}]c luster \textbackslash{}[26\textbackslash{}].T he model of F x suggested here, while speculative, provides for a novel structure through the interaction of two iron-sulfur clusters while preserving the fundamental stoichiometry of the Photosystem I components. This research was supported by grants from the National Science Foundation to JHG (DMB-8517391) and DMK (DMB-8216447). Copyright: Copyright 2014 Elsevier B.V., All rights reserved.",
year = "1987",
month = mar,
day = "25",
doi = "10.1016/0005-2728(87)90087-9",
language = "English (US)",
volume = "891",
pages = "94--98",
journal = "BBA - Bioenergetics",
issn = "0005-2728",
publisher = "Elsevier B.V.",
number = "1",
}