TY - JOUR
T1 - Structure and mechanism of Zn2+-transporting P-type ATPases
AU - Wang, Kaituo
AU - Sitsel, Oleg
AU - Meloni, Gabriele
AU - Autzen, Henriette Elisabeth
AU - Andersson, Magnus
AU - Klymchuk, Tetyana
AU - Nielsen, Anna Marie
AU - Rees, Douglas C
AU - Nissen, Poul
AU - Gourdon, Pontus Emanuel
PY - 2014/10/23
Y1 - 2014/10/23
N2 - Zinc isan essential micronutrient for all living organisms. It is required for signalling and proper functioning of a range of proteins involved in, for example, DNA binding and enzymatic catalysis1. In prokaryotes and photosynthetic eukaryotes, Zn21-transporting P-type ATPases of class IB (ZntA) are crucial for cellular redistribution and detoxification ofZn21and relatedelements2,3. Here we present crystal structures representing the phosphoenzyme ground state (E2P) and a dephosphorylation intermediate (E2·Pi)of ZntA from Shigella sonnei, determined at 3.2Å and 2.7Å resolution, respectively. The structures reveal a similar fold to Cu1-ATPases, with an amphipathic helix at the membrane interface. Aconserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular ZnH2+- ions by the transporter. The E2P structure displays a wide extracellular release pathway reaching the invariant residues at the high-affinity site, including C392, C394 and D714.Thepathway closes in theE2·Pi state, inwhich D714 interacts with the conserved residueK693,which possibly stimulates ZnH2+- release as a built-in counter ion, as has been proposed for H+-ATPases. Indeed, transport studies in liposomes provide experimental support for ZntA activity without counter transport. These findings suggest a mechanistic link betweenPIB-typeZnH2+-ATPases and PIII-typeH+-ATPases and at the same time show structural featuresof the extracellular release pathway that resemble PII-type ATPases such as the sarcoplasmic/endoplasmic reticulum CaH2+-ATPase4,5 (SERCA) and Na+,K+-ATPase6.These findings considerably increase our understanding of zinc transport in cells and represent new possibilities for biotechnology and biomedicine.
AB - Zinc isan essential micronutrient for all living organisms. It is required for signalling and proper functioning of a range of proteins involved in, for example, DNA binding and enzymatic catalysis1. In prokaryotes and photosynthetic eukaryotes, Zn21-transporting P-type ATPases of class IB (ZntA) are crucial for cellular redistribution and detoxification ofZn21and relatedelements2,3. Here we present crystal structures representing the phosphoenzyme ground state (E2P) and a dephosphorylation intermediate (E2·Pi)of ZntA from Shigella sonnei, determined at 3.2Å and 2.7Å resolution, respectively. The structures reveal a similar fold to Cu1-ATPases, with an amphipathic helix at the membrane interface. Aconserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular ZnH2+- ions by the transporter. The E2P structure displays a wide extracellular release pathway reaching the invariant residues at the high-affinity site, including C392, C394 and D714.Thepathway closes in theE2·Pi state, inwhich D714 interacts with the conserved residueK693,which possibly stimulates ZnH2+- release as a built-in counter ion, as has been proposed for H+-ATPases. Indeed, transport studies in liposomes provide experimental support for ZntA activity without counter transport. These findings suggest a mechanistic link betweenPIB-typeZnH2+-ATPases and PIII-typeH+-ATPases and at the same time show structural featuresof the extracellular release pathway that resemble PII-type ATPases such as the sarcoplasmic/endoplasmic reticulum CaH2+-ATPase4,5 (SERCA) and Na+,K+-ATPase6.These findings considerably increase our understanding of zinc transport in cells and represent new possibilities for biotechnology and biomedicine.
U2 - 10.1038/nature13618
DO - 10.1038/nature13618
M3 - Journal article
C2 - 25132545
SN - 0028-0836
VL - 514
SP - 518
EP - 522
JO - Nature
JF - Nature
IS - 7523
ER -