KOPS - Das Institutionelle Repositorium der Universität Konstanz

Crystal structure of Ca<sup>2+</sup>/H<sup>+</sup> antiporter protein YfkE reveals the mechanisms of Ca<sup>2+</sup> efflux and its pH regulation

Crystal structure of Ca2+/H+ antiporter protein YfkE reveals the mechanisms of Ca2+ efflux and its pH regulation

Zitieren

Dateien zu dieser Ressource

Prüfsumme: MD5:d227c85172174e6a6b9f0decfda3d120

WU, Mousheng, Shuilong TONG, Sandro WALTERSPERGER, Kay DIEDERICHS, Meitian WANG, Lei ZHENG, 2013. Crystal structure of Ca2+/H+ antiporter protein YfkE reveals the mechanisms of Ca2+ efflux and its pH regulation. In: Proceedings of the National Academy of Sciences. 110(28), pp. 11367-11372. ISSN 0027-8424. eISSN 1091-6490

@article{Wu2013-07-09Cryst-26310, title={Crystal structure of Ca2+/H+ antiporter protein YfkE reveals the mechanisms of Ca2+ efflux and its pH regulation}, year={2013}, doi={10.1073/pnas.1302515110}, number={28}, volume={110}, issn={0027-8424}, journal={Proceedings of the National Academy of Sciences}, pages={11367--11372}, author={Wu, Mousheng and Tong, Shuilong and Waltersperger, Sandro and Diederichs, Kay and Wang, Meitian and Zheng, Lei} }

Waltersperger, Sandro Proceedings of the National Academy of Sciences of the United States of America : PNAS ; 110 (2013), 28. - S. 11367-11372 Tong, Shuilong Wang, Meitian 2014-02-07T13:50:23Z Wu, Mousheng Tong, Shuilong Wang, Meitian Zheng, Lei eng deposit-license Diederichs, Kay Waltersperger, Sandro 2013-07-09 Zheng, Lei Diederichs, Kay 2014-02-07T13:50:23Z Crystal structure of Ca<sup>2+</sup>/H<sup>+</sup> antiporter protein YfkE reveals the mechanisms of Ca<sup>2+</sup> efflux and its pH regulation Ca<sup>2+</sup> efflux by Ca<sup>2+</sup> cation antiporter (CaCA) proteins is important for maintenance of Ca<sup>2+</sup> homeostasis across the cell membrane. Recently, the monomeric structure of the prokaryotic Na<sup>+</sup>/Ca<sup>2+</sup> exchanger (NCX) antiporter NCX_Mj protein from Methanococcus jannaschii shows an outward-facing conformation suggesting a hypothesis of alternating substrate access for Ca<sup>2+</sup> efflux. To demonstrate conformational changes essential for the CaCA mechanism, we present the crystal structure of the Ca<sup>2+</sup>/H<sup>+</sup> antiporter protein YfkE from Bacillus subtilis at 3.1-Å resolution. YfkE forms a homotrimer, confirmed by disulfide crosslinking. The protonated state of YfkE exhibits an inward-facing conformation with a large hydrophilic cavity opening to the cytoplasm in each protomer and ending in the middle of the membrane at the Ca<sup>2+</sup>-binding site. A hydrophobic “seal” closes its periplasmic exit. Four conserved α-repeat helices assemble in an X-like conformation to form a Ca<sup>2+</sup>/H<sup>+</sup> exchange pathway. In the Ca2+-binding site, two essential glutamate residues exhibit different conformations compared with their counterparts in NCX_Mj, whereas several amino acid substitutions occlude the Na<sup>+</sup>-binding sites. The structural differences between the inward-facing YfkE and the outward-facing NCX_Mj suggest that the conformational transition is triggered by the rotation of the kink angles of transmembrane helices 2 and 7 and is mediated by large conformational changes in their adjacent transmembrane helices 1 and 6. Our structural and mutational analyses not only establish structural bases for mechanisms of Ca<sup>2+</sup>/H<sup>+</sup> exchange and its pH regulation but also shed light on the evolutionary adaptation to different energy modes in the CaCA protein family. Wu, Mousheng

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

Wu_263100.pdf 70

Das Dokument erscheint in:

KOPS Suche


Stöbern

Mein Benutzerkonto