6RTC

Structure of murine Solute Carrier 26 family member A9 (Slc26a9) anion transporter in the inward-facing state

Summary for 6RTC

• Entry DOI: 10.2210/pdb6rtc/pdb
• Related: 6RTF
• EMDB information: 4997 4998
• Descriptor: Solute carrier family 26 member 9,Solute carrier family 26 member 9 (1 entity in total)
• Functional Keywords: slc26 family, anion transporter, membrane protein structure, transport mechanism, cryo-em, single particle, membrane protein
• Biological source: Mus musculus (Mouse); More
• Total number of polymer chains: 2
• Total formula weight: 141195.28

Authors

Sawicka, M.,Walter, J.D.,Dutzler, R. (deposition date: 2019-05-23, release date: 2019-07-24, Last modification date: 2024-05-22)

Primary citation

Walter, J.D.,Sawicka, M.,Dutzler, R.
Cryo-EM structures and functional characterization of murine Slc26a9 reveal mechanism of uncoupled chloride transport.
Elife, 8:-, 2019

PubMed Abstract: The epithelial anion transporter SLC26A9 contributes to airway surface hydration and gastric acid production. Colocalizing with CFTR, SLC26A9 has been proposed as a target for the treatment of cystic fibrosis. To provide molecular details of its transport mechanism, we present cryo-EM structures and a functional characterization of murine Slc26a9. These structures define the general architecture of eukaryotic SLC26 family members and reveal an unusual mode of oligomerization which relies predominantly on the cytosolic STAS domain. Our data illustrates conformational transitions of Slc26a9, supporting a rapid alternate-access mechanism which mediates uncoupled chloride transport with negligible bicarbonate or sulfate permeability. The characterization of structure-guided mutants illuminates the properties of the ion transport path, including a selective anion binding site located in the center of a mobile module within the transmembrane domain. This study thus provides a structural foundation for the understanding of the entire SLC26 family and potentially facilitates their therapeutic exploitation.

PubMed: 31339488
DOI: 10.7554/eLife.46986

Experimental method

ELECTRON MICROSCOPY (3.96 Å)