4FG6

Structure of EcCLC E148A mutant in Glutamate

4FG6 の概要

• エントリーDOI: 10.2210/pdb4fg6/pdb
• 分子名称: H(+)/Cl(-) exchange transporter ClcA, Fab fragment (Heavy chain), Fab fragment (Light chain) (3 entities in total)
• 機能のキーワード: transporter, membrane, transport protein
• 由来する生物種: Escherichia coli K-12; 詳細
• 細胞内の位置: Cell inner membrane ; Multi- pass membrane protein : P37019
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 193024.27

構造登録者

Feng, L.,MacKinnon, R. (登録日: 2012-06-04, 公開日: 2012-07-04, 最終更新日: 2023-09-13)

主引用文献

Feng, L.,Campbell, E.B.,MacKinnon, R.
Molecular mechanism of proton transport in CLC Cl-/H+ exchange transporters.
Proc.Natl.Acad.Sci.USA, 109:11699-11704, 2012

PubMed Abstract: CLC proteins underlie muscle, kidney, bone, and other organ system function by catalyzing the transport of Cl(-) ions across cell and organellar membranes. Some CLC proteins are ion channels while others are pumps that exchange Cl(-) for H(+). The pathway through which Cl(-) ions cross the membrane has been characterized, but the transport of H(+) and the principle by which their movement is coupled to Cl(-) movement is not well understood. Here we show that H(+) transport depends not only on the presence of a specific glutamate residue but also the presence of Cl(-) ions. H(+) transport, however, can be isolated and analyzed in the absence of Cl(-) by mutating the glutamate to alanine and adding carboxylate-containing molecules to solution, consistent with the notion that H(+) transfer is mediated through the entry of a carboxylate group into the anion pathway. Cl(-) ions and carboxylate interact with each other strongly. These data support a mechanism in which the glutamate carboxylate functions as a surrogate Cl(-) ion, but it can accept a H(+) and transfer it between the external solution and the central Cl(-) binding site, coupled to the movement of 2 Cl(-) ions.

PubMed: 22753511
DOI: 10.1073/pnas.1205764109

実験手法

X-RAY DIFFRACTION (3.019 Å)