4I0U

Improved structure of Thermotoga maritima CorA at 2.7 A resolution

4I0U の概要

• エントリーDOI: 10.2210/pdb4i0u/pdb
• 分子名称: Magnesium transport protein CorA, MAGNESIUM ION, CHLORIDE ION, ... (7 entities in total)
• 機能のキーワード: magnesium/cobalt transport, metal transport, membrane protein, cora
• 由来する生物種: Thermotoga maritima
• 細胞内の位置: Cell inner membrane; Multi-pass membrane protein: Q9WZ31
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 419905.54

構造登録者

Nordin, N.,Guskov, A.,Phua, T.,Sahaf, N.,Xia, Y.,Lu, S.Y.,Eshaghi, H.,Eshaghi, S. (登録日: 2012-11-19, 公開日: 2013-03-06, 最終更新日: 2024-03-20)

主引用文献

Nordin, N.,Guskov, A.,Phua, T.,Sahaf, N.,Xia, Y.,Lu, S.Y.,Eshaghi, H.,Eshaghi, S.
Exploring the structure and function of Thermotoga maritima CorA reveals the mechanism of gating and ion selectivity in Co2+/Mg2+ transport.
Biochem.J., 451:365-374, 2013

PubMed Abstract: The CorA family of divalent cation transporters utilizes Mg2+ and Co2+ as primary substrates. The molecular mechanism of its function, including ion selectivity and gating, has not been fully characterized. Recently we reported a new structure of a CorA homologue from Methanocaldococcus jannaschii, which provided novel structural details that offered the conception of a unique gating mechanism involving conversion of an open hydrophilic gate into a closed hydrophobic one. In the present study we report functional evidence for this novel gating mechanism in the Thermotoga maritima CorA together with an improved crystal structure of this CorA to 2.7 Å (1 Å=0.1 nm) resolution. The latter reveals the organization of the selectivity filter to be similar to that of M. jannaschii CorA and also the previously unknown organization of the second signature motif of the CorA family. The proposed gating is achieved by a helical rotation upon the binding of a metal ion substrate to the regulatory binding sites. Additionally, our data suggest that the preference of this CorA for Co2+ over Mg2+ is controlled by the presence of threonine side chains in the channel. Finally, the roles of the intracellular metal-binding sites have been assigned to increased thermostability and regulation of the gating. These mechanisms most likely apply to the entire CorA family as they are regulated by the highly conserved amino acids.

PubMed: 23425532
DOI: 10.1042/BJ20121745

実験手法

X-RAY DIFFRACTION (2.7 Å)