A single mutation converts bacterial Na+-transporting rhodopsin into an H+ transporter

作者：Mamedov Mahir D; Mamedov Adalyat M; Bertsova Yulia V; Bogachev Alexander V^*

来源：FEBS LETTERS, 2016, 590(17): 2827-2835.

DOI：10.1002/1873-3468.12324

• Pump-to-pump conversion
• rhodopsin
• sodium transport

Na+-rhodopsins are light-driven pumps used by marine bacteria to extrude Na+ ions from the cytoplasm. We show here that replacement of Gln123 on the cytoplasmic side of the ion-conductance channel with aspartate or glutamate confers H+ transport activity to the Na+-rhodopsin from Dokdonia sp. PRO95. The Q123E variant could transport H+ out of Escherichia coli cells in a medium containing 100 mM Na+ and SCN- as the penetrating anion. The rates of the photocycle steps of this variant were only marginally dependent on Na+, and the major electrogenic steps were the decays of the K and O intermediates.

• 出版日期2016-9