A Gene Cluster Involved in Metal Homeostasis in the Cyanobacterium
            <i>Synechocystis</i>
            sp. Strain PCC 6803

García-Domínguez, Mario; López‐Maury, Luis; Florencio, Francisco J.; Reyes, José Carlos Castañeda

doi:10.1128/jb.182.6.1507-1514.2000

Cited by 94 publications

(96 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In Synechococcus, there is another zinc sensor, SmtB, which is closely related to ZiaR and regulates SmtA, which in turn triggers internal zinc sequestration by metallothionein [31]. Regarding nickel, cobalt and zinc sensing and tolerance in Synechocystis, García-Domínguez et al [32] identified a gene cluster composed of nine ORFs. Overexpression of the nickel response operon was also observed in the presence of cobalt.…”

Section: Response To Metal Stressmentioning

confidence: 99%

Proteomic analyses of the response of cyanobacteria to different stress conditions

Castielli¹,

Cerda²,

Navarro³

et al. 2009

FEBS Letters

View full text Add to dashboard Cite

a b s t r a c tCyanobacteria are significant contributors to global photosynthetic productivity, thus making it relevant to study how the different environmental stresses can alter their physiological activities. Here, we review the current research work on the response of cyanobacteria to different kinds of stress, mainly focusing on their response to metal stress as studied by using the modern proteomic tools. We also report a proteomic analysis of plastocyanin and cytochrome c 6 deletion mutants of the cyanobacterium Synechocystis sp. PCC 6803 grown under copper or iron deprivation, as compared to wild-type cells, so as to get a further understanding of the metal homeostasis in cyanobacteria and their response to changing environmental conditions.

show abstract

Section: Response To Metal Stressmentioning

confidence: 99%

Proteomic analyses of the response of cyanobacteria to different stress conditions

Castielli¹,

Cerda²,

Navarro³

et al. 2009

FEBS Letters

View full text Add to dashboard Cite

show abstract

“…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).…”

mentioning

confidence: 99%

“…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).…”

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

“…The nickel-sensing/ responding system served as the trial regulator because the inducer Ni 2ϩ is easy to control. Improvements in the lysis system also are expected, because the lysis genes can be controlled by other cyanobacterial inducible promoters responding to other signals such as nutrient starvation (28), growth phase (29), environmental stress (30), or other metal ions (21). The cyanobacteria programmed lysis system has other uses in addition to biofuel extraction.…”

Section: Discussionmentioning

confidence: 99%

Nickel-inducible lysis system in Synechocystis sp. PCC 6803

Liu

Curtiss

2009

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We designed and constructed a controllable inducing lysis system in Synechocystis sp. PCC 6803 to facilitate extracting lipids for biofuel production. Several bacteriophage-derived lysis genes were integrated into the genome and placed downstream of a nickel-inducible signal transduction system. We applied 3 strategies: (i) directly using the phage lysis cassette, (ii) constitutively expressing endolysin genes while restricting holin genes, and (iii) combining lysis genes from different phages. Significant autolysis was induced in the Synechocystis sp. PCC 6803 cells with this system by the addition of NiSO4. Our inducible cyanobacterial lysing system eliminates the need for mechanical or chemical cell breakage and could facilitate recovery of biofuel from cyanobacteria.biofuel ͉ phage lysis genes P hotosynthetic microorganisms, including eukaryotic algae and cyanobacteria, are being optimized to overproduce numerous products of value (1). Because of the global energy shortage and climate change caused by greenhouse gas emission, the scientific community has focused on developing renewable biofuels from photosynthetic microorganisms (2). Cyanobacteria are excellent organisms for biofuel production. Unlike algae, their genomes are relatively easy to manipulate. They are efficient at converting solar energy, and, unlike energy crops, they can be grown on non-arable land (3). We thus have selected Cyanobacterium Synechocystis sp. PCC 6803 (hereafter referred to as Synechocystis 6803) as a model organism to develop methods for easy recovery of lipids for use in biofuel production.The first goal of our research was to disrupt the cyanobacterial cell envelope to facilitate lipid recovery from biomass. Seog et al. (4) used various methods, such as sonication, French press, bead-beater, and lyophilization, to disrupt the cell envelops of the alga Botryococcus braunii. Extraction was 1.96 times more efficient using the bead-beater method than by using solvents alone, suggesting that a proper method of cell disruption could facilitate lipid extraction by damaging the cell wall. However, the bead-beater method is not economical for large amounts of biomass. There are some alternative cell-breakage methods, e.g., pulsed electric field (5) and hydrolytic enzymes (6), but all these methods add additional cost and reduce the overall utility of the process. Our strategy is simply to make the cyanobacteria lyse at the appropriate time.The cyanobacterial cell envelope is composed of 4 layers (7) (Fig. 1): the external surface layers (such as S-layers and carbohydrate structures), the outer membrane, the polypeptidoglycan layer (8), and the cytoplasmic membrane. Despite the overall gram-negative structure, the peptidoglycan layer found in cyanobacteria is considerably thicker than that of most gramnegative bacteria (8). In addition, the degree of crosslinking between the peptidoglycan chains within the cell wall layer of cyanobacteria (56-63%) is far higher than that in most gramnegative bacteria (20-33%) (9).To break up the pepti...

show abstract

A Gene Cluster Involved in Metal Homeostasis in the Cyanobacterium Synechocystis sp. Strain PCC 6803

Cited by 94 publications

References 55 publications

Proteomic analyses of the response of cyanobacteria to different stress conditions

Proteomic analyses of the response of cyanobacteria to different stress conditions

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

Nickel-inducible lysis system in Synechocystis sp. PCC 6803

Contact Info

Product

Resources

About