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bioRxiv · 10.1101/2020.12.29.424758

Zinc Dependent Conformational Changes in the Cation Diffusion Facilitator YiiP from S. oneidensis

Lopez-Redondo, M.·Fan, S.·Koide, A.·Koide, S.·Beckstein, O.·Stokes, D. L.
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Abstract

YiiP is a secondary transporter that couples Zn2+ transport to the proton motive force. Structural studies of YiiP from prokaryotes as well as Znt8 from humans revealed three different Zn2+ sites and a conserved homodimeric architecture. These structures define the inward-facing and outward-facing states that characterize the archetypal alternating access mechanism of transport. To study effects of Zn2+ binding on the conformational transition, we have used a YiiP/Fab complex for single-particle cryo-EM together with Molecular Dynamics simulation to compare structures of YiiP from S. oneidensis in presence and absence of Zn2+. Without Zn2+, YiiP exhibits enhanced flexibility and adopts a novel conformation that appears to be an intermediate state. The transition closes a hydrophobic gate and is controlled by the Zn2+ site at the cytoplasmic membrane interface. This work enhances our understanding of individual Zn2+ binding sites and their role in the conformational dynamics that governs the transport cycle.

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Lopez-Redondo, M., Fan, S., Koide, A., Koide, S., Beckstein, O., Stokes, D. L.. 2020-12-30. Zinc Dependent Conformational Changes in the Cation Diffusion Facilitator YiiP from S. oneidensis. https://doi.org/10.1101/2020.12.29.424758

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