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Second system for potassium transport in Streptococcus faecalis.

H Kobayashi
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Abstract

It has been reported that the accumulation of K+ by Streptococcus faecalis is mediated by a transport system which required both ATP and the proton motive force (Bakker and Harold, J. Biol. Chem. 255:433-440, 1980). My results indicate that S. faecalis has a second transport system for K+. The features of this system are as follows: (i) the system is driven by ATP (or a derivative of ATP) and does not require the proton motive force; (ii) the system is normally absent in the wild-type strain but can be derepressed by lowering rhe intracellular concentration of K+; (iii) the pH optimum of this system is about 8.5, and no detectable K+ is accumulated at pH values below 6.5; and (iv) the rate of Rb+ accumulation by this system is very low. These properties are quite different from those of the transport system described by Bakker and Harold. Therefore, I propose that S. faecalis has two K+ transport systems.

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Adenosine TriphosphateBiological Transport, ActiveDicyclohexylcarbodiimideEnterococcus faecalisHydrogen-Ion ConcentrationKineticsMutationPotassiumProtonsJournal ArticleResearch Support, Non-U.S. Gov't

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H Kobayashi. 1982. Second system for potassium transport in Streptococcus faecalis.. https://doi.org/10.1128/jb.150.2.506-511.1982

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