Structural insights into sodium transport by the oxaloacetate decarboxylase sodium pump

Abstract
Data availability
Article and author information
Metrics

Abstract

The oxaloacetate decarboxylase sodium pump (OAD) is a unique primary-active transporter that utilizes the free energy derived from oxaloacetate decarboxylation for sodium transport across the cell membrane. It is composed of 3 subunits: the a subunit catalyzes carboxyl-transfer from oxaloacetate to biotin, the membrane integrated β subunit catalyzes the subsequent carboxyl-biotin decarboxylation and the coupled sodium transport, the γ subunit interacts with the a and β subunits and stabilizes the OAD complex. We present here structure of the Salmonella typhimurium OAD βγ sub-complex. The structure revealed that the β and γ subunits form a β₃γ₃ hetero-hexamer with extensive interactions between the subunits and shed light on the OAD holo-enzyme assembly. Structure-guided functional studies provided insights into the sodium binding sites in the β subunit and the coupling between carboxyl-biotin decarboxylation and sodium transport by the OAD β subunit.

Data availability

The cryo-EM structure of the StOAD βγ sub-complex and related data have been deposited into the protein data bank (https://www.pdb.org) and the electron microscopy data bank (https://www.ebi.ac.uk/pdbe/emdb/), with the accession numbers 6IWW and EMD-9743, respectively. The crystal structure of the StOAD βγ sub-complex and the diffraction data have been deposited into the protein data bank with the accession number 6IVA. Source data for Figure 4c-d, Figure 4-figure supplement 1, Figure 5b-c, Figure 5-figure supplement 1, Figure 6a, Figure 6-figure supplement 1, and Figure 6-figure supplement 2a-b are provided.

The following data sets were generated

1. Xu X
2. Shi H
3. Zhang X
4. Xiang S
(2018) Cryo-EM structure of the S. typhimurium oxaloacetate decarboxylase betagamma sub-complex
Protein Data Bank, 6IWW.

http://www.rcsb.org/structure/6IWW
1. Xu X
2. Xiang S
(2018) Crystal structure of the S. typhimurium oxaloacetate decarboxylase betagamma sub-complex
Protein Data Bank, 6IVA.

http://www.rcsb.org/structure/6IVA

Article and author information

Author details

Xin Xu

Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin, China

Competing interests
The authors declare that no competing interests exist.
Huigang Shi

National Laboratory of Biomacromolecules, CAS center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China

Competing interests
The authors declare that no competing interests exist.
Xiaowen Gong

CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China

Competing interests
The authors declare that no competing interests exist.
Ying Gao

CAS Key Laboratory of Nutrition, Metabolism and Food safety, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China

Competing interests
The authors declare that no competing interests exist.
Xinzheng Zhang

National Laboratory of Biomacromolecules, CAS center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China

For correspondence
xzzhang@ibp.ac.cn

Competing interests
The authors declare that no competing interests exist.
Song Xiang

Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin, China

For correspondence
xiangsong@tmu.edu.cn

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0001-9314-4684

Funding

National Natural Science Foundation of China (31870769)

Song Xiang

National Natural Science Foundation of China (31570743)

Song Xiang

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.