4BPQ

Structure and substrate induced conformational changes of the secondary citrate-sodium symporter CitS revealed by electron crystallography

4BPQ の概要

• エントリーDOI: 10.2210/pdb4bpq/pdb
• EMDBエントリー: 2387
• 分子名称: CITRATE\:SODIUM SYMPORTER (1 entity in total)
• 機能のキーワード: transport protein, secondary transporter, membrane protein
• 由来する生物種: KLEBSIELLA PNEUMONIAE
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 54162.44

構造登録者

Kebbel, F.,Kurz, M.,Arheit, M.,Gruetter, M.G.,Stahlberg, H. (登録日: 2013-05-27, 公開日: 2013-07-17, 最終更新日: 2024-05-08)

主引用文献

Kebbel, F.,Kurz, M.,Arheit, M.,Grutter, M.G.,Stahlberg, H.
Structure and Substrate-Induced Conformational Changes of the Secondary Citrate/Sodium Symporter Cits Revealed by Electron Crystallography.
Structure, 21:1243-, 2013

PubMed Abstract: The secondary Na+/citrate symporter CitS of Klebsiella pneumoniae is the best-characterized member of the 2-hydroxycarboxylate transporter family. The recent projection structure gave insight into its overall structural organization. Here, we present the three-dimensional map of dimeric CitS obtained with electron crystallography. Each monomer has 13 a-helical transmembrane segments; six are organized in a distal helix cluster and seven in the central dimer interface domain. Based on structural analyses and comparison to VcINDY, we propose a molecular model for CitS, assign the helices, and demonstrate the internal structural symmetry. We also present projections of CitS in several conformational states induced by the presence and absence of sodium and citrate as substrates. Citrate binding induces a defined movement of a helices within the distal helical cluster. Based on this, we propose a substrate translocation site and conformational changes that are in agreement with the transport model of ‘‘alternating access’’.

PubMed: 23810698
DOI: 10.1016/J.STR.2013.05.011

実験手法

ELECTRON CRYSTALLOGRAPHY (6 Å)