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-Structure paper
タイトル | Deciphering ion transport and ATPase coupling in the intersubunit tunnel of KdpFABC. |
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ジャーナル・号・ページ | Nat Commun, Vol. 12, Issue 1, Page 5098, Year 2021 |
掲載日 | 2021年8月24日 |
著者 | Jakob M Silberberg / Robin A Corey / Lisa Hielkema / Charlott Stock / Phillip J Stansfeld / Cristina Paulino / Inga Hänelt / |
PubMed 要旨 | KdpFABC, a high-affinity K pump, combines the ion channel KdpA and the P-type ATPase KdpB to secure survival at K limitation. Here, we apply a combination of cryo-EM, biochemical assays, and MD ...KdpFABC, a high-affinity K pump, combines the ion channel KdpA and the P-type ATPase KdpB to secure survival at K limitation. Here, we apply a combination of cryo-EM, biochemical assays, and MD simulations to illuminate the mechanisms underlying transport and the coupling to ATP hydrolysis. We show that ions are transported via an intersubunit tunnel through KdpA and KdpB. At the subunit interface, the tunnel is constricted by a phenylalanine, which, by polarized cation-π stacking, controls K entry into the canonical substrate binding site (CBS) of KdpB. Within the CBS, ATPase coupling is mediated by the charge distribution between an aspartate and a lysine. Interestingly, individual elements of the ion translocation mechanism of KdpFABC identified here are conserved among a wide variety of P-type ATPases from different families. This leads us to the hypothesis that KdpB might represent an early descendant of a common ancestor of cation pumps. |
リンク | Nat Commun / PubMed:34429416 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.1 - 3.2 Å |
構造データ | EMDB-12478, PDB-7nnl: EMDB-12482, PDB-7nnp: |
化合物 | ChemComp-K: ChemComp-CDL: ChemComp-ACP: ChemComp-RB: |
由来 |
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キーワード | MEMBRANE PROTEIN / P-type ATPase / superfamily of K+ transporters (SKT) / potassium uptake system / ATP analogue / Rb substitution / intersubunit tunnel |