Structural insights into sodium transport by the oxaloacetate decarboxylase sodium pump.

Xin Xu, Huigang Shi, Xiaowen Gong, Pu Chen, Ying Gao, Xinzheng Zhang, Song Xiang

eLife 2020 May 27

filter terms:

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 α 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 α 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. © 2020, Xu et al.

Citation

Xin Xu, Huigang Shi, Xiaowen Gong, Pu Chen, Ying Gao, Xinzheng Zhang, Song Xiang. Structural insights into sodium transport by the oxaloacetate decarboxylase sodium pump. eLife. 2020 May 27;9