4A48

Crosstalk between Cu(I) and Zn(II) homeostasis

4A48 の概要

• エントリーDOI: 10.2210/pdb4a48/pdb
• 関連するPDBエントリー: 2GCF 2XMW 4A46 4A47 4A4J
• 分子名称: PROBABLE COPPER-TRANSPORTING ATPASE PACS, ZINC ION, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: transport protein, copper homeostasis, zinc homeostasis, atx1, metal-transporting atpases
• 由来する生物種: SYNECHOCYSTIS
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: P73241
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 14974.06

構造登録者

Badarau, A.,Basle, A.,Firbank, S.J.,Denninson, C. (登録日: 2011-10-07, 公開日: 2012-12-12, 最終更新日: 2023-12-20)

主引用文献

Badarau, A.,Basle, A.,Firbank, S.J.,Dennison, C.
Investigating the Role of Zinc and Copper Binding Motifs of Trafficking Sites in the Cyanobacterium Synechocystis Pcc 6803.
Biochemistry, 52:6816-, 2013

PubMed Abstract: 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 (ZiaAN and PacSN, 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 ZiaAN has been introduced into Atx1 and PacSN, and the motifs of Atx1 and PacSN swapped. The motif sequence can tune Cu(I) affinity only approximately 3-fold. However, the introduction of the ZiaAN motif (MDCTSC) dramatically increases the Zn(II) affinity of both Atx1 and PacSN by up to 2 orders of magnitude. The Atx1 mutant with the ZiaAN motif crystallizes as a side-to-side homodimer very similar to that found for [Cu(I)2-Atx1]2 ( Badarau et al. Biochemistry 2010 , 49 , 7798 ). In a crystal structure of the PacSN mutant possessing the ZiaAN motif (PacSN(ZiaAN)), 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 ZiaAN are due to the ability of the carboxylate to ligate this metal ion. Comparison of the Zn(II) sites in PacSN(ZiaAN) structures provides additional insight into Zn(II) trafficking in cyanobacteria.

PubMed: 24050657
DOI: 10.1021/BI400492T

実験手法

X-RAY DIFFRACTION (1.4 Å)