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Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803

[Image: see text] Although zinc and copper are required by proteins with very different functions, these metals can be delivered to cellular locations by homologous metal transporters within the same organism, as demonstrated by the cyanobacterial (Synechocystis PCC 6803) zinc exporter ZiaA and thyl...

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Autores principales: Badarau, Adriana, Baslé, Arnaud, Firbank, Susan J., Dennison, Christopher
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2013
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793899/
https://www.ncbi.nlm.nih.gov/pubmed/24050657
http://dx.doi.org/10.1021/bi400492t
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author Badarau, Adriana
Baslé, Arnaud
Firbank, Susan J.
Dennison, Christopher
author_facet Badarau, Adriana
Baslé, Arnaud
Firbank, Susan J.
Dennison, Christopher
author_sort Badarau, Adriana
collection PubMed
description [Image: see text] Although zinc and copper are required by proteins with very different functions, these metals can be delivered to cellular locations by homologous metal transporters within the same organism, as demonstrated by the cyanobacterial (Synechocystis PCC 6803) zinc exporter ZiaA and thylakoidal copper importer PacS. The N-terminal metal-binding domains of these transporters (ZiaA(N) and PacS(N), respectively) have related ferredoxin folds also found in the metallochaperone Atx1, which delivers copper to PacS, but differ in the residues found in their M/IXCXXC metal-binding motifs. To investigate the role of the nonconserved residues in this region on metal binding, the sequence from ZiaA(N) has been introduced into Atx1 and PacS(N), and the motifs of Atx1 and PacS(N) swapped. The motif sequence can tune Cu(I) affinity only approximately 3-fold. However, the introduction of the ZiaA(N) motif (MDCTSC) dramatically increases the Zn(II) affinity of both Atx1 and PacS(N) by up to 2 orders of magnitude. The Atx1 mutant with the ZiaA(N) motif crystallizes as a side-to-side homodimer very similar to that found for [Cu(I)(2)–Atx1](2) ( Badarau et al. Biochemistry2010, 49, 779820726513). In a crystal structure of the PacS(N) mutant possessing the ZiaA(N) motif (PacS(N)(ZiaA(N))), the Asp residue from the metal-binding motif coordinates Zn(II). This demonstrates that the increased Zn(II) affinity of this variant and the high Zn(II) affinity of ZiaA(N) are due to the ability of the carboxylate to ligate this metal ion. Comparison of the Zn(II) sites in PacS(N)(ZiaA(N)) structures provides additional insight into Zn(II) trafficking in cyanobacteria.
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spelling pubmed-37938992013-10-10 Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803 Badarau, Adriana Baslé, Arnaud Firbank, Susan J. Dennison, Christopher Biochemistry [Image: see text] Although zinc and copper are required by proteins with very different functions, these metals can be delivered to cellular locations by homologous metal transporters within the same organism, as demonstrated by the cyanobacterial (Synechocystis PCC 6803) zinc exporter ZiaA and thylakoidal copper importer PacS. The N-terminal metal-binding domains of these transporters (ZiaA(N) and PacS(N), respectively) have related ferredoxin folds also found in the metallochaperone Atx1, which delivers copper to PacS, but differ in the residues found in their M/IXCXXC metal-binding motifs. To investigate the role of the nonconserved residues in this region on metal binding, the sequence from ZiaA(N) has been introduced into Atx1 and PacS(N), and the motifs of Atx1 and PacS(N) swapped. The motif sequence can tune Cu(I) affinity only approximately 3-fold. However, the introduction of the ZiaA(N) motif (MDCTSC) dramatically increases the Zn(II) affinity of both Atx1 and PacS(N) by up to 2 orders of magnitude. The Atx1 mutant with the ZiaA(N) motif crystallizes as a side-to-side homodimer very similar to that found for [Cu(I)(2)–Atx1](2) ( Badarau et al. Biochemistry2010, 49, 779820726513). In a crystal structure of the PacS(N) mutant possessing the ZiaA(N) motif (PacS(N)(ZiaA(N))), the Asp residue from the metal-binding motif coordinates Zn(II). This demonstrates that the increased Zn(II) affinity of this variant and the high Zn(II) affinity of ZiaA(N) are due to the ability of the carboxylate to ligate this metal ion. Comparison of the Zn(II) sites in PacS(N)(ZiaA(N)) structures provides additional insight into Zn(II) trafficking in cyanobacteria. American Chemical Society 2013-09-19 2013-10-01 /pmc/articles/PMC3793899/ /pubmed/24050657 http://dx.doi.org/10.1021/bi400492t Text en Copyright © 2013 American Chemical Society Terms of Use CC-BY (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html)
spellingShingle Badarau, Adriana
Baslé, Arnaud
Firbank, Susan J.
Dennison, Christopher
Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803
title Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803
title_full Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803
title_fullStr Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803
title_full_unstemmed Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803
title_short Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis PCC 6803
title_sort investigating the role of zinc and copper binding motifs of trafficking sites in the cyanobacterium synechocystis pcc 6803
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793899/
https://www.ncbi.nlm.nih.gov/pubmed/24050657
http://dx.doi.org/10.1021/bi400492t
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