Novel Zinc-containing Ferredoxin Family in Thermoacidophilic Archaea

Iwasaki, Toshio; Suzuki, Toshiharu; Kon, Takahide; Imai, Takeo; Urushiyama, Akio; Ohmori, Daijiro; Oshima, Tairo

doi:10.1074/jbc.272.6.3453

Cited by 17 publications

(28 citation statements)

References 44 publications

(67 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Through chemical analysis, electron paramagnetic resonance (EPR) and low temperature resonance Raman spectroscopy, it was demonstrated that the ferredoxin contains one 1ϩ,0 cluster, one 2ϩ,1ϩ cluster, and one tightly bound zinc center (14), thus indicating the existence of "zinc-containing ferredoxins" among phylogenetically diverse members of several thermoacidophilic Archaea (14). Although the presence of a tightly bound zinc center is one of the most unique properties of the archaeal zinc-containing ferredoxins, the structural details of the zinc site have been characterized only for ferredoxin from Sulfolobus sp.…”

mentioning

confidence: 99%

“…Thermoplasma acidophilum strain HO-62 cells, originally isolated from hot sulfur springs at Ohwakudani solfataric field in Hakone, Japan, were routinely cultivated at pH 1.8 and at 56°C in 10-and 30-liter acid-resistant fermenters as described by Yasuda et al (20), and zinc-containing ferredoxin was purified as described previously (14). Sulfolobus sp.…”

mentioning

confidence: 99%

“…Herein, we report the XAS analysis of zinc-containing ferredoxins from these two phylogenetically distantly related Archaea, Thermoplasma acidophilum strain HO-62 and Sulfolobus sp. strain 7 (6,14,15), to characterize the structural properties of the zinc and iron coordination environments. We also report cloning and sequencing of the zfx gene encoding zinc-containing ferredoxin of T. acidophilum strain HO-62 (zfx for zinc-containing ferredoxin) and its flanking regions, to clarify its gene organization and the distribution of zinc-containing ferredoxin homologs in thermophilic organisms.…”

mentioning

confidence: 99%

“…tion (8,14) and the other being the membrane-bound aerobic respiratory chain containing multiple b-and d-type cytochromes (21). 2 The pioneering work by Kerscher and co-workers (8) has shown that T. acidophilum strain DSM 1728 contains a bacterial-type ferredoxin functioning as an electron acceptor of the cognate 2-oxoacid:ferredoxin oxidoreductase.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Structural Conservation of the Isolated Zinc Site in Archaeal Zinc-containing Ferredoxins as Revealed by X-ray Absorption Spectroscopic Analysis and Its Evolutionary Implications

Cosper

Stålhandske

Iwasaki

et al. 1999

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

The zfx gene encoding a zinc-containing ferredoxin from Thermoplasma acidophilum strain HO-62 was cloned and sequenced. It is located upstream of two genes encoding an archaeal homolog of nascent polypeptide-associated complex ␣ subunit and a tRNA nucleotidyltransferase. This gene organization is not conserved in several euryarchaeoteal genomes. The multiple sequence alignments of the zfx gene product suggest significant sequence similarity of the ferredoxin core fold to that of a low potential 8Fe-containing dicluster ferredoxin without a zinc center. The tightly bound zinc site of zinc-containing ferredoxins from two phylogenetically distantly related Archaea, T. acidophilum HO-62 and Sulfolobus sp. strain 7, was further investigated by x-ray absorption spectroscopy. The zinc K-edge x-ray absorption spectra of both archaeal ferredoxins are strikingly similar, demonstrating that the same zinc site is found in T. acidophilum ferredoxin as in Sulfolobus sp. ferredoxin, which suggests the structural conservation of isolated zinc binding sites among archaeal zinc-containing ferredoxins. The sequence and spectroscopic data provide the common structural features of the archaeal zinc-containing ferredoxin family.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Structural Conservation of the Isolated Zinc Site in Archaeal Zinc-containing Ferredoxins as Revealed by X-ray Absorption Spectroscopic Analysis and Its Evolutionary Implications

Cosper

Stålhandske

Iwasaki

et al. 1999

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…Upon elution, a brown band was eluted with 1.6±0 m ammonium sulfate in 50 mm Tris/HCl buffer, pH 7.5, and then concentrated by ammonium sulfate precipitation. Maintaining the pH at 7.5 is important during the procedure in the presence of ammonium sulfate, which prevented the possible conversion of the 7Fe to the 6Fe cluster as reported at pH 5 in the presence of ammonium sulfate [12,15]. The protein was concentrated with Centricon 10 (Amicon), and then applied to a gel-filtration column, Bio-Gel P-60 (1.5 Â 120 cm), equilibrated with 50 mm sodium phosphate (pH 6.9).…”

Section: Construction Of Plasmid For the Mutant Ferredoxin And Preparmentioning

confidence: 99%

Zinc and an N‐terminal extra stretch of the ferredoxin from a thermoacidophilic archaeon stabilize the molecule at high temperature

Kojoh

Matsuzawa

Wakagi

1999

European Journal of Biochemistry

View full text Add to dashboard Cite

Ferredoxin from the thermoacidophilic archaeon Sulfolobus sp. strain 7 has a 36-residue extra domain at its N-terminus and a 67-residue core domain carrying two iron±sulfur clusters. A zinc ion is held at the interface of the two domains through tetrahedral coordination of three histidine residues (26, 219 and 234) and one aspartic acid residue (276) [Fujii, T., Hata, Y., Oozeki, M., Moriyama, H., Wakagi, T., Tanaka, N. & Oshima, T. (1997) Biochemistry 36, 1505±1513]. To elucidate the roles of the novel zinc ion and the extra N-terminal domain, a series of truncated mutants was constructed: G1, V12, S17, G23, L31 and V38, which lack residues 0, 11, 16, 22, 30 and 37 starting from the N-terminus, respectively. A mutant with two histidine residues each replaced by an alanine residue, H16A/H19A, was also constructed. All the mutant ferredoxins had two iron±sulfur clusters, while zinc was retained only in G1 and V12. The thermal stability of the proteins was investigated by monitoring A 408 ; the melting temperature (T m ) was <109 8C for the natural ferredoxin, <109 8C for G1, 97.6 8C for V12, 89.0 8C for S17, 89.2 8C for G23, 89.3 8C for L31, 82.1 8C for V38, and 89.4 8C for H16A/H19A. K m and V max values of 2-oxoglutarate:ferredoxin oxidoreductase for natural ferredoxin, G1, S17 and L31 were similar, suggesting that electron-accepting activities were not affected by the deletion. The combination of CD and fluorescent spectroscopic analyses with truncated mutant S17 indicated that not only the clusters but also the secondary and tertiary structures were simultaneously degraded at a T m around 89 8C. These results unequivocally demonstrate that the zinc ion and certain parts, but not all, of the extra sequence stretch in the N-terminal domain are responsible not for function but for thermal stabilization of the molecule.Keywords: archaea; ferredoxin; stability; zinc.Ferredoxin is a small protein widely distributed among all living organisms, with one or more redox center(s) composed of acid-labile sulfur and non-heme iron participating in various oxidation±reduction processes in the cell [1,2]. Archaeal ferredoxins are not classified into a simple`archaeal type', but into different categories based on both the clusters and amino-acid sequences; the ferredoxins from thermoacidophilic archaea belong to the 7Fe-bicluster type, those from anaerobic hyperthermophilic archaea to the 4Fe-monocluster type, those from extremely halophilic archaea to the 2Fe-type, and so on [2,3]. It is, however, striking that they play a common role as electron acceptors in the CoA-dependent oxidative decarboxylation of 2-oxoacids, which is seldom found in eubacteria or eukaryotes [4]. In contrast with the widely found 2-oxoacid dehydrogenase multienzyme complex with NAD(P) as an electron acceptor [5], 2-oxoacid:ferredoxin oxidoreductase (OFOR) is a very simple enzyme comprising one to four subunits, with a total molecular mass of around 103±260 kDa [6,7].The primary structure, comprising 103 amino acid residues, of the ferredoxin from the...

show abstract

Electron Transport to Nitrogenase: Diverse Routes for a Common Destination

Saeki

Nitrogen Fixation: Origins, Applications, and Research Progress

View full text Add to dashboard Cite

Nitrogenase, which consists of dinitrogenase (e.g., the MoFe protein) and dinitrogenase reductase (the Fe protein), catalyzes the biological reduction of molecular nitrogen (N 2 ) according to the following equation: N 2 + (6+2n) H + + (6+2n) e + (12+4n) MgATP 2 NH 3 + n H 2 + (12+4n) MgADP + (12+4n) Pi (where n 1 depending on the availability of both H + and e )Electrons are first transferred to dinitrogenase reductase, which in turn donates electrons to dinitrogenase. This reaction is common to all three conventional nitrogenases; the molybdenum-containing nitrogenase as well as the alternative vanadium-containing and the iron-only nitrogenases. It does not apply to the unusual N 2 -fixation system reported for the thermophile, Streptomyces thermoautotrophicus, which was isolated from a burning charcoal pile (Gadkari et al., 1992;Ribbe et al., 1997). As shown in the above equation, the availability of reducing power is as important as the availability of ATP for the throughput of the nitrogenase reaction. When the supply of reducing power is limited, the value of n increases (Haaker and Klugkist, 1987) and, as a consequence, net fixation of N 2 decreases, with more reducing equivalents diverted towards H 2 production.

show abstract

Novel Zinc-containing Ferredoxin Family in Thermoacidophilic Archaea

Cited by 17 publications

References 44 publications

Structural Conservation of the Isolated Zinc Site in Archaeal Zinc-containing Ferredoxins as Revealed by X-ray Absorption Spectroscopic Analysis and Its Evolutionary Implications

Structural Conservation of the Isolated Zinc Site in Archaeal Zinc-containing Ferredoxins as Revealed by X-ray Absorption Spectroscopic Analysis and Its Evolutionary Implications

Zinc and an N‐terminal extra stretch of the ferredoxin from a thermoacidophilic archaeon stabilize the molecule at high temperature

Electron Transport to Nitrogenase: Diverse Routes for a Common Destination

Contact Info

Product

Resources

About