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-Structure paper
タイトル | Cryo-EM structures of KdpFABC suggest a K transport mechanism via two inter-subunit half-channels. |
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ジャーナル・号・ページ | Nat Commun, Vol. 9, Issue 1, Page 4971, Year 2018 |
掲載日 | 2018年11月26日 |
![]() | C Stock / L Hielkema / I Tascón / D Wunnicke / G T Oostergetel / M Azkargorta / C Paulino / I Hänelt / ![]() ![]() ![]() |
PubMed 要旨 | P-type ATPases ubiquitously pump cations across biological membranes to maintain vital ion gradients. Among those, the chimeric K uptake system KdpFABC is unique. While ATP hydrolysis is accomplished ...P-type ATPases ubiquitously pump cations across biological membranes to maintain vital ion gradients. Among those, the chimeric K uptake system KdpFABC is unique. While ATP hydrolysis is accomplished by the P-type ATPase subunit KdpB, K has been assumed to be transported by the channel-like subunit KdpA. A first crystal structure uncovered its overall topology, suggesting such a spatial separation of energizing and transporting units. Here, we report two cryo-EM structures of the 157 kDa, asymmetric KdpFABC complex at 3.7 Å and 4.0 Å resolution in an E1 and an E2 state, respectively. Unexpectedly, the structures suggest a translocation pathway through two half-channels along KdpA and KdpB, uniting the alternating-access mechanism of actively pumping P-type ATPases with the high affinity and selectivity of K channels. This way, KdpFABC would function as a true chimeric complex, synergizing the best features of otherwise separately evolved transport mechanisms. |
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手法 | EM (単粒子) |
解像度 | 3.7 - 4.0 Å |
構造データ | |
化合物 | ![]() ChemComp-K: |
由来 |
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