Dataset Information

Temperature dependence of protein-water interactions in a gated yeast aquaporin.

ABSTRACT: Regulation of aquaporins is a key process of living organisms to counteract sudden osmotic changes. Aqy1, which is a water transporting aquaporin of the yeast Pichia pastoris, is suggested to be gated by chemo-mechanical stimuli as a protective regulatory-response against rapid freezing. Here, we tested the influence of temperature by determining the X-ray structure of Aqy1 at room temperature (RT) at 1.3?Å resolution, and by exploring the structural dynamics of Aqy1 during freezing through molecular dynamics simulations. At ambient temperature and in a lipid bilayer, Aqy1 adopts a closed conformation that is globally better described by the RT than by the low-temperature (LT) crystal structure. Locally, for the blocking-residue Tyr31 and the water molecules inside the pore, both LT and RT data sets are consistent with the positions observed in the simulations at room-temperature. Moreover, as the temperature was lowered, Tyr31 adopted a conformation that more effectively blocked the channel, and its motion was accompanied by a temperature-driven rearrangement of the water molecules inside the channel. We therefore speculate that temperature drives Aqy1 from a loosely- to a tightly-blocked state. This analysis provides high-resolution structural evidence of the influence of temperature on membrane-transport channels.

SUBMITTER: Aponte-Santamaria C

PROVIDER: S-EPMC5479825 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

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Temperature dependence of protein-water interactions in a gated yeast aquaporin.

Aponte-Santamaría Camilo C Fischer Gerhard G Båth Petra P Neutze Richard R de Groot Bert L BL

Scientific reports 20170621 1

Regulation of aquaporins is a key process of living organisms to counteract sudden osmotic changes. Aqy1, which is a water transporting aquaporin of the yeast Pichia pastoris, is suggested to be gated by chemo-mechanical stimuli as a protective regulatory-response against rapid freezing. Here, we tested the influence of temperature by determining the X-ray structure of Aqy1 at room temperature (RT) at 1.3 Å resolution, and by exploring the structural dynamics of Aqy1 during freezing through mole ...[more]

PMID: 28638135

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Dataset Information

Temperature dependence of protein-water interactions in a gated yeast aquaporin.

Publications

Temperature dependence of protein-water interactions in a gated yeast aquaporin.

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