InterPro : IPR020884

Name  Glutathione-regulated potassium-efflux system protein KefB Short Name  K_H_efflux_KefB
Type  Family Description  The CPA2 family is a moderately large family (over 100 sequenced members) from bacteria, archaea and eukaryotes. Among the functionally well-characterised members of the family are (1) the KefB/KefC K+ efflux proteins of Escherichia coliwhich may be capable of catalysing both K+/H+ antiport and K+ uniport, depending on conditions [, ], (2) the Na+/H+ antiporter of Enterococcus hirae[]and (3) the K+/H+ antiporter of Saccharomyces cerevisiae. It has been proposed that under normal physiological conditions, these proteins may function by essentially the same mechanism [].KefC and KefB of E. coli are responsible for glutathione-gated K+ efflux [, ]. Each of these proteins consists of a transmembrane hydrophobic N-terminal domain, and a less well-conserved C-terminal hydrophilic domain. Each protein interacts with a second protein encoded by genes that overlap the gene encoding the primary transporter. The KefB ancillary protein is YheR. The ancillary proteins stimulate transport activity about 10-fold []. They are important for cell survival during exposure to toxic metabolites, possibly because they can release K+, allowing H+ uptake. Activation of the KefB or KefC K+ efflux system only occurs in the presence of glutathione and a reactive electrophile such as methylglyoxal or N-ethylmaleimide. Formation of the methylglyoxal-glutathione conjugate, S-lactoylglutathione, is catalysed by glyoxalase I, and S-lactoylglutathione activates KefB and KefC []. H+ uptake (acidification of the cytoplasm) accompanying or following K+ efflux may serve as a further protective mechanism against electrophile toxicity [, ]. Inhibition of transport by glutathione is enhanced by NADH []. This entry represents the Glutathione-regulated potassium-efflux system protein KefB.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

4 Contains

Id Name Short Name Type
IPR016040 NAD(P)-binding domain NAD(P)-bd_dom Domain
IPR006153 Cation/H+ exchanger Cation/H_exchanger Domain
IPR003148 Regulator of K+ conductance, N-terminal RCK_N Domain
IPR004771 K+/H+ exchanger K/H_exchanger Domain

0 Found In

0 Parent Features

9 Publications

First Author Title Year Journal Volume Pages
Fujisawa M Three two-component transporters with channel-like properties have monovalent cation/proton antiport activity. 2007 Proc Natl Acad Sci U S A 104 13289-94
Munro AW The cloning and DNA sequence of the gene for the glutathione-regulated potassium-efflux system KefC of Escherichia coli. 1991 Mol Microbiol 5 607-16
Bakker EP High-affinity potassium uptake system in Bacillus acidocaldarius showing immunological cross-reactivity with the Kdp system from Escherichia coli. 1987 J Bacteriol 169 4342-8
Waser M Cloning and disruption of a putative NaH-antiporter gene of Enterococcus hirae. 1992 J Biol Chem 267 5396-400
Reizer J The putative Na+/H+ antiporter (NapA) of Enterococcus hirae is homologous to the putative K+/H+ antiporter (KefC) of Escherichia coli. 1992 FEMS Microbiol Lett 73 161-3
Ferguson GP Activation of potassium channels during metabolite detoxification in Escherichia coli. 1993 Mol Microbiol 9 1297-303
Ferguson GP Survival during exposure to the electrophilic reagent N-ethylmaleimide in Escherichia coli: role of KefB and KefC potassium channels. 1997 J Bacteriol 179 1007-12
Miller S Identification of an ancillary protein, YabF, required for activity of the KefC glutathione-gated potassium efflux system in Escherichia coli. 2000 J Bacteriol 182 6536-40
MacLean MJ The role of glyoxalase I in the detoxification of methylglyoxal and in the activation of the KefB K+ efflux system in Escherichia coli. 1998 Mol Microbiol 27 563-71

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)