Bacterial Response to Copper in the Environment: Copper Resistance in Escherichia coli as a Model System

Lee, B. T. O.; Brown, Nigel L.; Rogers, Sue; Bergemann, Andrew D.; Camakaris, J.; Rouch, Duncan A.

doi:10.1007/978-3-642-74206-4_34

Cited by 16 publications

(16 citation statements)

References 9 publications

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“…The data presented in this paper, together with earlier results (Rouch, 1986;Rouch et aL, 1989a, b;Lee et aL, 1990) and information on the subcellular localization of the sequence-related cop-encoded proteins in P. syringae pv. tomato (Cha and Cooksey, 1991), allow elaboration of the copper resistance encoded by pco in E. coil We propose that during initial exposure to high copper the system works to decrease cellular copper uptake (Rouch, 1986;Rouch et aL, 1989b), resulting in reduced accumulation of copper.…”

Section: A Hypothesis For Pco-and Cop-encoded Copper Resistancesupporting

confidence: 76%

“…In contrast to the reduced accumulation in log-phase cells containing pco, after growth to stationary phase in various copper concentrations, plasmid-containing cells accumulated eightfold more copper than the plasmidless sensitive cells, as measured by atomic absorption spectroscopy (Lee et aL, 1990). Increased accumulation during complete growth was found also with P. syringae pv.…”

Section: Copper Transportmentioning

confidence: 79%

“…The reduced uptake appears to be due to copper export (this report; Rouch (1986)). Stationary-phase pco-containing E. coli cells accumulate more copper than plasmidless sensitive cells (Lee et aL, 1990). Although the localization of this accumulated copper is not known, it may be on the PcoA and PcoC proteins, by analogy with the cop system whereby copper is known to be sequestered in the periplasm by the CopA and CopC proteins.…”

Section: A Hypothesis For Pco-and Cop-encoded Copper Resistancementioning

confidence: 99%

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Molecular genetics and transport analysis of the copper‐resistance determinant (pco) from Escherichia coli plasmid pRJ1004

Brown¹,

Barrett²,

Camakaris³

et al. 1995

Molecular Microbiology

224

222

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The copper-resistance determinant (pco) of Escherichia coli plasmid pRJ1004 was cloned and sequenced. Tn1000 transposon mutagenesis identified four complementation groups, mutations in any of which eliminated copper resistance. DNA sequence analysis showed that the four complementation groups contained six open reading frames, designated pco-ABCDRS. The protein product sequences derived from the nucleotide sequence show close homology between this copper-resistance system and the cop system of a plasmid pPT23D of Pseudomonas syringae pv. tomato. The PcoR and PcoS protein sequences show homology to the family of two-component sensor/responder phosphokinase regulatory systems. A seventh reading frame (pcoE) was identified from DNA sequence data, and lies downstream of a copper-regulated promoter. Transport assays with 64Cu(II) showed that the resistant cells containing the plasmid had reduced copper accumulation during the log phase of growth, while increased accumulation had previously been observed during stationary phase. Chromosomal mutants defective in cellular copper management were obtained and characterized. In two of these mutants pco resistance was rendered totally inactive, whilst in another two mutants pco complemented the defective genes. These data indicate that plasmid-borne copper resistance in E. coli is linked with chromosomal systems for copper management.

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Section: A Hypothesis For Pco-and Cop-encoded Copper Resistancesupporting

confidence: 76%

Section: Copper Transportmentioning

confidence: 79%

Section: A Hypothesis For Pco-and Cop-encoded Copper Resistancementioning

confidence: 99%

See 1 more Smart Citation

Molecular genetics and transport analysis of the copper‐resistance determinant (pco) from Escherichia coli plasmid pRJ1004

Brown¹,

Barrett²,

Camakaris³

et al. 1995

Molecular Microbiology

224

222

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“…Recent DNA sequencing of the plasmidpco system defined a region of seven structural genes, pcoA to pcoD, pcoR, pcoS, and pcoE. The amino acid sequence identities between pco and cop systems are 76% for PcoA and CopA, 54% for PcoB and CopB, 60% for PcoC and CopC, 38% for PcoD and CopD (37,59,64), and 61% for PcoR and CopR (48). However, the biochemical mechanisms of copper resistance in thepco system are not.…”

mentioning

confidence: 99%

Molecular cloning, chromosomal mapping, and sequence analysis of copper resistance genes from Xanthomonas campestris pv. juglandis: homology with small blue copper proteins and multicopper oxidase

et al. 1994

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Copper-resistant strains of Xanthomonas campestris pv. juglandis occur in walnut orchards throughout northern California. The copper resistance genes from a copper-resistant strain C5 ofX. campestris pv.juglkndis were cloned and located on a 4.9-kb ClaI fragment, which hybridized only to DNA of copper-resistant strains ofX. campestris pv.juglandis, and was part of an approximately 20-kb region which was conserved among such strains of X. campestris pv. juglandis. Hybridization analysis indicated that the copper resistance genes were located on the chromosome. Plasmids conferring copper resistance were not detected in copper-resistant strains, nor did mating with copper-sensitive strains result in copper-resistant transconjugants. Copper resistance genes from X. campestris pv. juglandis shared nucleotide sequence similarity with copper resistance genes from Pseudomonas syringae pv. tomato, P. syringae, and X. campestris pv. vesicatoria. DNA sequence analysis of the 4.9-kb fragment from strain C5 revealed that the sequence had an overall G+C content of 58.7%, and four open reading frames (ORFI to ORF4), oriented in the same direction. All four ORFs were required for full expression of copper resistance, on the basis of Tn3-spice insertional inactivation and deletion analysis. The predicted amino acid sequences of ORF1 to ORF4 showed 65, 45, 47, and 40%o identity with CopA, CopB, CopC, and CopD, respectively, from P. syringae pv. tomato. The most conserved regions are ORF1 and CopA and the C-terminal region (166 amino acids from the C terminus) of ORF2 and CopB. The hydrophobicity profiles of each pair of predicted polypeptides are similar except for the N terminus of ORF2 and CopB. Four histidine-rich polypeptide regions in ORF1 and CopA strongly resembled the copper-binding motifs of small blue copper proteins and multicopper oxidases, such as fungal laccases, plant ascorbate oxidase, and human ceruloplasmin. Putative copper ligands of the ORFI polypeptide product are proposed, indicating that the polypeptide of ORF1 might bind four copper ions: one type 1, one type 2, and two type 3.Walnut blight caused by Xanthomonas campestris pv. juglandis is an important disease of Persian (English) walnuts (Juglans regia L.) in California, Oregon, and other states (4,6,43). Copper-containing bactericides have been used for many decades to reduce the severity of this disease and other plant bacterial diseases (7, 52). However, the efficacy of copper has been reduced by the occurrence of copper-resistant bacterial strains. Plasmid-encoded resistance to copper has been demonstrated for several phytopathogenic bacteria and some other bacteria, including Pseudomonas syringae pv. tomato, a pathogen of tomato (8) non-self-transmissible plasmid approximately 100 kb in size (17). By using low-stringency posthybridization conditions, it was shown (77) that Cur genes in X campestris pv. vesicatoria from Florida, Oklahoma, and California are closely related and that they have similarities to the cop operon of P. syringae pv. tomato.The...

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“…Copper induction is dependent on two genes, pcoR and pcoS, that are linked to the structural pcoABCD genes (6,40). A predicted amino acid sequence derived from the nucleotide sequence ofpcoR has been published (6,21), and it shows strong similarities to several activator components of two-component regulatory systems. Unpublished sequence information also indicates that pcoS is related to the sensor components of the twocomponent systems (40).…”

mentioning

confidence: 99%

A two-component regulatory system required for copper-inducible expression of the copper resistance operon of Pseudomonas syringae

1993

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Specific induction of the copper resistance operon (cop) promoter from Pseudomonas syringae was measured by beta-galactosidase production from a cop promoter-lacZ fusion. Induction of the cop promoter in P. syringae pv. syringae required trans-acting factors from copper resistance plasmid pPT23D, from which cop was originally cloned. Tn5 mutagenesis of pPT23D was used to localize two complementation groups immediately downstream from copABCD. Cloning and sequencing of the DNA in this region revealed two genes, copR and copS, expressed in the same orientation as the cop operon but from a separate constitutive promoter. The amino acid sequence deduced from these genes showed distinct similarities to known two-component regulatory systems, including PhoB-PhoR and OmpR-EnvZ. In addition, CopR showed strong similarity to copper resistance activator protein PcoR from Escherichia coli. Functional chromosomal homologs to copRS activated the cop promoter, in a copper-inducible manner, in copper-resistant or -sensitive strains of P. syringae pv. tomato and other Pseudomonas species. This implies that copper-inducible gene regulation is associated with a common chromosomally encoded function, as well as plasmid-borne copper resistance, in Pseudomonas spp.

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Bacterial Response to Copper in the Environment: Copper Resistance in Escherichia coli as a Model System

Cited by 16 publications

References 9 publications

Molecular genetics and transport analysis of the copper‐resistance determinant (pco) from Escherichia coli plasmid pRJ1004

Molecular genetics and transport analysis of the copper‐resistance determinant (pco) from Escherichia coli plasmid pRJ1004

Molecular cloning, chromosomal mapping, and sequence analysis of copper resistance genes from Xanthomonas campestris pv. juglandis: homology with small blue copper proteins and multicopper oxidase

A two-component regulatory system required for copper-inducible expression of the copper resistance operon of Pseudomonas syringae

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