Protein Domain : IPR020884

Type:  Family Name:  Glutathione-regulated potassium-efflux system protein KefB
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. Short Name:  K_H_efflux_KefB

0 Child Features

4 Contains

DB identifier Type Name
IPR004771 Domain K+/H+ exchanger
IPR006153 Domain Cation/H+ exchanger
IPR016040 Domain NAD(P)-binding domain
IPR003148 Domain Regulator of K+ conductance, N-terminal

1 Cross References

Identifier
MF_01412

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0015503 IPR020884
GO:0006813 IPR020884
GO:0005886 IPR020884

3 Ontology Annotations

GO Term Gene Name
GO:0015503 IPR020884
GO:0006813 IPR020884
GO:0005886 IPR020884

0 Parent Features

0 Proteins

9 Publications

First Author Title Year Journal Volume Pages PubMed ID
            17679694
            2046548
            2957359
            1312090
            1325937
            7934942
            9023177
            11053405
            9489668