Nickel and iron incorporation into soluble hydrogenase of Alcaligenes eutrophus

Friedrich, Cornelius G.; Suetin, S; Lohmeyer, Michael

doi:10.1007/bf00454928

Cited by 27 publications

(19 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In A. eutrophus, the incorporation of nickel into the hydrogenases takes place during protein synthesis. Attempts to reactivate nickel-free apoprotein in vitro by the addition of nickel were unsuccessfull (15). The pleiotropic nature of hoxD and hoxE mutations suggests that the gene products of these loci direct a common step in hydrogenase synthesis.…”

Section: Discussionmentioning

confidence: 99%

Three trans-acting regulatory functions control hydrogenase synthesis in Alcaligenes eutrophus

Eberz

Friedrich

1991

J Bacteriol

View full text Add to dashboard Cite

Random Tn5 mutagenesis of the regulatory region of megaplasmid pHG1 of Alcaligenes eutrophus led to the identification of three distinct loci designated hoxA, hoxD, and hoxE. Sequencing of the hoxA locus revealed an open reading frame which could code for a polypeptide of 482 amino acids with a molecular mass of 53.5 kDa. A protein of comparable apparent molecular mass was detected in heterologous expression studies with a plasmid-borne copy of the hoxA gene. Amino acid alignments revealed striking homologies between HoxA and the transcriptional activators NifA and NtrC of Klebsiella pneumoniae and HydG of Escherichia coli. HoxA- mutants of A. eutrophus lacked both NAD-reducing soluble hydrogenase and membrane-bound hydrogenase. In HoxA- mutants, the synthesis of beta-galactosidase from a hoxS'-'lacZ operon fusion was drastically reduced, indicating that HoxA is essential for the transcription of hydrogenase genes. Mutants defective in hoxD and hoxE also lacked the catalytic activities of the two hydrogenases; however, in contrast to HoxA- mutants, they contained immunologically detectable NAD-reducing soluble hydrogenase and membrane-bound hydrogenase proteins, although at a reduced level. The low hydrogenase content in the HoxD- and HoxE- mutants correlated with a decrease in beta-galactosidase synthesized under the direction of a hoxS'-'lacZ operon fusion. Thus, hoxD and hoxE apparently intervene both in the regulation of hydrogenase synthesis and in subsequent steps leading to the formation of catalytically active enzymes.

show abstract

Section: Discussionmentioning

confidence: 99%

Three trans-acting regulatory functions control hydrogenase synthesis in Alcaligenes eutrophus

Eberz

Friedrich

1991

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…Nickel is classified as a borderline metal ion because it has both soft and hard metal properties and can bind to sulfur, nitrogen, and oxygen groups (3). In many bacteria, nickel is required for enzymes such as urease, CO dehydrogenase, and hydrogenase (5,10). However, excess nickel is toxic.…”

mentioning

confidence: 99%

NreB from Achromobacter xylosoxidans 31A Is a Nickel-Induced Transporter Conferring Nickel Resistance

et al. 2001

View full text Add to dashboard Cite

There are two distinct nickel resistance loci on plasmid pTOM9 from Achromobacter xylosoxidans 31A, ncc and nre. Expression of the nreB gene was specifically induced by nickel and conferred nickel resistance on both A. xylosoxidans 31A and Escherichia coli. E. coli cells expressing nreB showed reduced accumulation of Ni 2؉ , suggesting that NreB mediated nickel efflux. The histidine-rich C-terminal region of NreB was not essential but contributed to maximal Ni 2؉ resistance.Nickel is the 24th most abundant element in the earth's crust and has been detected in different media in all parts of the biosphere. Nickel is classified as a borderline metal ion because it has both soft and hard metal properties and can bind to sulfur, nitrogen, and oxygen groups (3). In many bacteria, nickel is required for enzymes such as urease, CO dehydrogenase, and hydrogenase (5, 10). However, excess nickel is toxic. Nickel binds to proteins and nucleic acids and frequently inhibits enzymatic activity, DNA replication, transcription, and translation (1). Several nickel-resistant bacteria have been isolated from heavy-metal-contaminated sites. Well-studied examples include Ralstonia metallidurans CH34 and Achromobacter xylosoxidans 31A (8, 24). The determinant responsible for nickel resistance in R. metallidurans CH34, cnr (cobalt-nickel resistance), encodes three regulatory genes (cnrY, cnrX, and cnrH) and three structural genes encoding the subunits of the Co-Ni efflux pump (cnrC, cnrB, and cnrA) (8,26). The cnr determinant is similar to the ncc determinant (nickel-cobalt-cadmium resistance) of A. xylosoxidans 31A. The proposed gene products for the efflux system CnrCBA and NccCBA are largely homologous to the gene products for the three subunits of the better-characterized CzcCBA cation-proton antiporter and probably have a similar function (16,17,27). In addition to the ncc locus, A. xylosoxidans 31A contains another distinct nickel resistance locus, nre, located on plasmid pTOM9. The nre locus confers low-level nickel resistance on both Ralstonia and Escherichia coli strains (24). The closest homologue of the deduced nreB gene product is NrsD from Synechocystis sp. strain PCC 6803 (6). Both NreB and NrsD belong to the major facilitator superfamily (MFS), and computer analysis indicates 12 putative transmembrane helices in each (11,20). Additionally, both proteins possess histidine-rich C termini possibly implicated in metal binding (6).In this study, we characterized the nre locus of A. xylosoxidans 31A and showed that only nreB is required for nickel resistance. In A. xylosoxidans, nreB was specifically induced by nickel but not by cobalt or zinc. The histidine-rich C terminus was not essential for NreB function but was necessary for maximum nickel resistance. E. coli cells harboring nreB showed reduced uptake of nickel compared to that of wild-type cells. The data support our hypothesis that NreB is a Ni 2ϩ transporter responsible for Ni 2ϩ efflux and resistance in A. xylosoxidans 31A and E. coli. MATERIALS AND METHODSBacterial...

show abstract

“…B-peptide antigens were formed by A. hydrogenophilus, A. ruhlandii, and Nocardia opaca with partial immunochemical identity to the A. eutrophus protein ( Fig. 4B; Table 1 subjected to chromatography on DEAE-cellulose as described previously (12). The fractions containing the B protein were pooled and concentrated 10-fold by Amicon filtration with a P-10 membrane.…”

Section: Resultsmentioning

confidence: 99%

“…Antibodies against the SDStreated B protein were produced as described by Friedrich et al (12). To eliminate a minor contaminating antibody not specific to the B protein, the purified immunoglobulin G antibodies were incubated with the soluble fraction of the plasmid-free mutant HF33 (at a 1:1 ratio on a protein basis) for 1 h at 37°C.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Purification and properties of a protein linked to the soluble hydrogenase of hydrogen-oxidizing bacteria

Kärst¹,

Suetin²,

Friedrich³

1987

J Bacteriol

View full text Add to dashboard Cite

In Alcaligenes eutrophus, the formation of the hydrogenases and of five new peptides is subject to the hydrogenase control system. Of these, the B peptide was purified to homogeneity. This protein (Mr, 37,500) was composed of two identical subunits (Mr,18,800). Antibodies against the B protein were used for its quantification by rocket immunoelectrophoresis. About 4% of the total protein consisted of the B protein; its molar ratio to the NAD-linked hydrogenase was about 4:1. The B protein appeared to be associated with the NAD-linked hydrogenase, as shown by gel filtration analysis with Sephadex G-200. The B protein was not detected in cells that had not expressed the hydrogenase proteins or that lacked the genetic information of the hydrogen-oxidizing character; it was also not detected in Tn5 insertional mutants that were unable to form soluble hydrogenase antigens. Immunochemical analysis of other species and genera than A. eutrophus revealed that only strains able to form a NAD-linked hydrogenase also formed B-protein antigens. The B protein is not required for the catalytic activity of soluble hydrogenase in vitro; its function is at present unknown.

show abstract

Nickel and iron incorporation into soluble hydrogenase of Alcaligenes eutrophus

Cited by 27 publications

References 27 publications

Three trans-acting regulatory functions control hydrogenase synthesis in Alcaligenes eutrophus

Three trans-acting regulatory functions control hydrogenase synthesis in Alcaligenes eutrophus

NreB from Achromobacter xylosoxidans 31A Is a Nickel-Induced Transporter Conferring Nickel Resistance

Purification and properties of a protein linked to the soluble hydrogenase of hydrogen-oxidizing bacteria

Contact Info

Product

Resources

About