Salmonella Research Today is a free monthly online journal that collates and summarizes the latest research about Salmonella, including details on salmonella typhimurium, food poisoning, infection, treatment.

pH-dependent gating in a FocA formate channel.

Lü W, Du J, Wacker T, Gerbig-Smentek E, Andrade SL, Einsle O

Lehrstuhl für Biochemie, Institut für organische Chemie und Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.

The formate transporter FocA was described to switch its mode of operation from a passive export channel at high external pH to a secondary active formate/H(+) importer at low pH. The crystal structure of Salmonella typhimurium FocA at pH 4.0 shows that this switch involves a major rearrangement of the amino termini of individual protomers in the pentameric channel. The amino-terminal helices open or block transport in a concerted, cooperative action that indicates how FocA is gated in a pH-dependent way. Electrophysiological studies show that the protein acts as a specific formate channel at pH 7.0 and that it closes upon a shift of pH to 5.1.

Published 15 April 2011 in Science, 332(6027): 352-4.
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[Abstract] [Full-text]

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[Abstract] [Full-text]

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