Is cytochrome aa3 from thermus thermophilus a single subunit oxidase?

Fee, James A.; Yoshida, Tatsuro; Lorence, Robert M.; Choc, Miles G.; Tarr, George E.; Findling, Karen L.

doi:10.1016/s0020-1693(00)95103-x

Cited by 13 publications

(26 citation statements)

References 3 publications

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“…The powder spectrum and the g anisotropy of the EPR spectrum of FL-M2 and subspectrum II found in the EPR spectrum of FL are similar to those of plant-type [2Fe-2S] ferredoxins, i.e., spinach ferredoxin ( [23]. This might suggest the presence, in the M2 motif, of one or two less electron-donating N/O ligands replacing one or two cysteine ligands.…”

Section: Epr Spectroscopy Of Anamorsinmentioning

confidence: 51%

“…We therefore assign subspectrum I to the Fe/S cluster bound to the M1 motif and subspectrum II to the Fe/S cluster bound to the M2 motif. Given that the oxidized FL sample is diamagnetic, the Mössbauer data of subspectra I and II, being characteristic of ferric irons, confirm that the Fe/S clusters bound to the M1 motif or the M2 motif are both 23]. In the latter system, the subspectrum with the higher isomer shift represents the two-histidinecoordinated ferric site.…”

Section: Mössbauer Spectroscopy Of Anamorsinmentioning

confidence: 85%

“…Although each [2Fe-2S] cluster bound to either the M1 motif or the M2 motif of anamorsin is ligated by four cysteine residues, the Mössbauer parameters of these [2Fe-2S] clusters in their reduced state share some features with the Rieske centers, having a two-histidine/two-cysteine coordination (Table 2). In particular, the simulations of the magnetic Mössbauer spectra at 4.2 K of the reduced [2Fe-2S] clusters in both 1-270 and FL show a high isomer shift of the ferrous sites, d = 0.70 and 0.71 mm s -1 (Table 2), resembling more that of the ferrous site in the Rieske center (d = 0.74 mm s -1 [23]) than that of the ferrous site in the four-cysteine-ligated cluster of [2Fe-2S] ferredoxins (d = 0.65 mm s -1 [28,38,39]). Moreover, the ferric and ferrous sites in the [2Fe-2S] ?…”

Section: Reduced Fl Constructmentioning

confidence: 99%

“…5, S1). For comparison, the corresponding values for putidaredoxin from Pseudomonas putida [28] and the Rieske protein from Thermus thermophilus are reported [23]. See Table S1 for details a Difference of isomer shifts…”

Section: Reduced Fl Constructmentioning

confidence: 99%

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Human anamorsin binds [2Fe–2S] clusters with unique electronic properties

et al. 2013

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The eukaryotic anamorsin protein family, which has recently been proposed to be part of an electron transfer chain functioning in the early steps of cytosolic iron-sulfur (Fe/S) protein biogenesis, is characterized by a largely unstructured domain (CIAPIN1) containing two conserved cysteine-rich motifs (CX 8 CX 2 CXC and CX 2 CX 7 CX 2 C) whose Fe/S binding properties and electronic structures are not well defined. Here, we found that (1) each motif in human anamorsin is able to bind independently a [2Fe-2S] cluster through its four cysteine residues, the binding of one cluster mutually excluding the binding of the second, (2) the reduced [2Fe-2S] ? clusters exhibit a unique electronic structure with considerable anisotropy in their coordination environment, different from that observed in reduced, plant-type and vertebratetype [2Fe-2S] ferredoxin centers, (3) the reduced cluster bound to the CX 2 CX 7 CX 2 C motif reveals an unprecedented valence localization-to-delocalization transition as a function of temperature, and (4) only the [2Fe-2S] cluster bound to the CX 8 CX 2 CXC motif is involved in the electron transfer with its physiological protein partner Ndor1. The unique electronic properties of both [2Fe-2S] centers can be interpreted by considering that both cysteine-rich motifs are located in a highly unstructured and flexible protein region, whose local conformational heterogeneity can induce anisotropy in metal coordination. This study contributes to the understanding of the functional role of the CIAPIN1 domain in the anamorsin family, suggesting that only the [2Fe-2S] cluster bound to the CX 8 CX 2 CXC motif is indispensable in the electron transfer chain assembling cytosolic Fe/S proteins.

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Section: Epr Spectroscopy Of Anamorsinmentioning

confidence: 51%

Section: Mössbauer Spectroscopy Of Anamorsinmentioning

confidence: 85%

Section: Reduced Fl Constructmentioning

confidence: 99%

Section: Reduced Fl Constructmentioning

confidence: 99%

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Human anamorsin binds [2Fe–2S] clusters with unique electronic properties

et al. 2013

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“…To ascribe the remaining two cysteines as ligands for an Fe-S cluster is rather unlikely. It is not impossible, though, as some [2Fe-2S] clusters are proposed to have up to two non-sulphur ligands [67,85,201].…”

Section: The "Large' or Nickel-binding Subunitmentioning

confidence: 99%

Nickel hydrogenases: in search of the active site

Albracht

1994

Biochimica et Biophysica Acta (BBA) - Bioenergetics

470

479

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Oxidized and reduced [2Fe–2S] clusters from an iron(I) synthon

et al. 2015

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Synthetic [2Fe-2S] clusters are often used to elucidate ligand effects on the reduction potentials and spectroscopy of natural electron transfer sites, which can have anionic Cys ligands or neutral His ligands. Current synthetic routes to [2Fe-2S] clusters are limited in their feasibility with a range of supporting ligands. Here we report a new synthetic route to synthetic [2Fe-2S] clusters, through oxidation of an iron(I) source with elemental sulfur. This method yields a neutral diketiminate-supported [2Fe-2S] cluster in the diiron(III) oxidized form. The oxidized [2Fe-2S] cluster can be reduced to a mixed valent iron(II)-iron(III) compound. Both the diferric and reduced mixed valent clusters are characterized using X-ray crystallography, Mössbauer spectroscopy, EPR spectroscopy and cyclic voltammetry. The reduced compound is particularly interesting because its X-ray crystal structure shows a difference in Fe-S bond lengths to one of the iron atoms, consistent with valence localization. The valence localization is also evident from Mössbauer spectroscopy.

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Is cytochrome aa3 from thermus thermophilus a single subunit oxidase?

Cited by 13 publications

References 3 publications

Human anamorsin binds [2Fe–2S] clusters with unique electronic properties

Human anamorsin binds [2Fe–2S] clusters with unique electronic properties

Nickel hydrogenases: in search of the active site

Oxidized and reduced [2Fe–2S] clusters from an iron(I) synthon

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