6QK6

Solution Structure of the Cd-loaded form of a Metallothionein from Helix Pomatia

6QK6 の概要

• エントリーDOI: 10.2210/pdb6qk6/pdb
• NMR情報: BMRB: 34356
• 分子名称: Cadmium-metallothionein, CADMIUM ION (2 entities in total)
• 機能のキーワード: metallothionein, cadmium protein, snail protein, helix pomatia, metal binding protein
• 由来する生物種: Helix pomatia (Roman snail)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7310.11

構造登録者

Zerbe, O.,Jurt, S.,Beil, A. (登録日: 2019-01-28, 公開日: 2019-12-18, 最終更新日: 2024-06-19)

主引用文献

Beil, A.,Jurt, S.,Walser, R.,Schonhut, T.,Guntert, P.,Palacios, O.,Atrian, S.,Capdevila, M.,Dallinger, R.,Zerbe, O.
The Solution Structure and Dynamics of Cd-Metallothionein fromHelix pomatiaReveal Optimization for Binding Cd over Zn.
Biochemistry, 58:4570-4581, 2019

PubMed Abstract: Metallothioneins (MTs) are cysteine-rich polypeptides that are naturally found coordinated to monovalent and/or divalent transition metal ions. Three metallothionein isoforms from the Roman snail are known. They differ in their physiological metal load and in their specificity for transition metal ions such as Cd (HpCdMT isoform) and Cu (HpCuMT isoform) or in the absence of a defined metal specificity (HpCd/CuMT isoform). We have determined the solution structure of the Cd-specific isoform (HpCdMT) by nuclear magnetic resonance spectroscopy using recombinant isotopically labeled protein loaded with Zn or Cd. Both structures display two-domain architectures, where each domain comprises a characteristic three-metal cluster similar to that observed in the β-domains of vertebrate MTs. The polypeptide backbone is well-structured over the entire sequence, including the interdomain linker. Interestingly, the two domains display mutual contacts, as observed before for the metallothionein of the snail , to which both N- and C-terminal domains are highly similar. Increasing the length of the linker motionally decouples both domains and removes mutual contacts between them without having a strong effect on the stability of the individual domains. The structures of Cd- and Zn-HpCdMT are nearly identical. However, N relaxation, in particular N rates, is accelerated for many residues of Zn-HpCdMT but not for Cd-HpCdMT, revealing the presence of conformational exchange effects. We suggest that this snail MT isoform is evolutionarily optimized for binding Cd rather than Zn.

PubMed: 31633358
DOI: 10.1021/acs.biochem.9b00830

実験手法

SOLUTION NMR