TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*2.A.37.1.1









Glutathione-regulated K+ efflux protein C, KefC; regulated by ancillary protein KefF (YabF)
Bacteria
Proteobacteria
KefCF of E. coli
KefC (P03819)
KefF (P0A754)
*2.A.37.1.2









Glutathione-regulated K+ efflux protein B, KefB; regulated by ancillary protein KefG (YheR)

Bacteria
Proteobacteria
KefBG of E. coli
KefB (P45522)
KefG (P0A756)
*2.A.37.1.3









The K + efflux pump, KefB (Wei et al., 2007)
Bacteria
Proteobacteria
KefB of Alkalimonas amylolytica (Q0ZAH7)
*2.A.37.1.4









K+ efflux antiporter 1, chloroplastic (AtKEA1).  Localizes to the chloroplast inner envelope membrane and is essential for normal osmoregulation (Kunz et al. 2014).

Eukaryota
Viridiplantae
KEA1 of Arabidopsis thaliana
*2.A.37.1.5









Inner membrane protein YbaL

Bacteria
Proteobacteria
YbaL of Escherichia coli
*2.A.37.1.6









K+ efflux - K+:H+ antiporter 3 (AtKEA3) of 776 aas and 13 TMSs.  Localizes to the thylakoid membrane of the chloroplast.  It modulates pmf partitioning through H+ efflux from the lumen, which is critical for photosynthetic acclimation after transitions from high to low light intensity (Armbruster et al. 2014; Kunz et al. 2014).

Eukaryota
Viridiplantae
KEA3 of Arabidopsis thaliana
*2.A.37.1.7









Chloroplastic K+ efflux antiporter 2, AtKEA2. Cation preference:  K+ > Cs+ > Li+ > Na+ (Aranda-Sicilia et al. 2012).  The N-terminal hydrophilic domain show sequence similarity to members of the MPA1-C family (8.A.3.1.2). Localizes to the chloroplast inner envelope membrane and plays a role in chloroplast integrity (Kunz et al. 2014).

Eukaryota
Viridiplantae
KEA2 of Arabidopsis thaliana
*2.A.37.1.8









K+ efflux antiporter 5 (AtKEA5)

Eukaryota
Viridiplantae
KEA5 of Arabidopsis thaliana
*2.A.37.1.9









Glutathione-regulated potassium-efflux system, KefB of 416 aas and 13 TMSs.

Bacteria
Proteobacteria
KefB of Helicobacter pylori
*2.A.37.1.10









CPA2 family member of 627 aas and 12 TMSs

Bacteria
Proteobacteria
CPA2 member of Simonsiella muelleri
*2.A.37.1.11









Transmembrane and coiled-coil domain 3,TMCO3 of 677 aas and 13 TMSs.  When mutated causes cornea guttata and anterior polar cataracts.  he encoding gene is expressed in the human cornea, lens capsule, and choroid-retinal pigment epithelium (Chen et al. 2016).

Eukaryota
Metazoa
TMCO3 of Homo sapiens
*2.A.37.1.12









Iron-regulated MagA protein.  Deletion mutants of magA show apparently normal magnetosomes and growth in spite of an early report to the contrary (Uebe et al. 2012).

Bacteria
Proteobacteria
MagA of Magnetospirillum sp. strain AMB-1
*2.A.37.2.1









Na+:H+ antiporter, NapA
Bacteria
Firmicutes
NapA of Enterococcus hirae
*2.A.37.2.2









The Na+/H+-K+ antiporter, GerN (spore germination protein-N) (Southworth et al., 2001).

Bacteria
Firmicutes
GerN of Bacillus cereus
*2.A.37.2.3









Spore germination protein, GrmA
Bacteria
Firmicutes
GrmA of Bacillus megaterium
*2.A.37.2.4









The high-affinity (Km(Na+)=0.7 mM) Na+(Li+):H+ thylakoid membrane antiporter, NhaS3 (essential for growth; promotes Na+ resistance; expressed in the presence of high CO2 concentrations; under circadian control (Tsunekawa et al. 2009).
Bacteria
Cyanobacteria
NhaS3 of Synechocystis sp. PCC6803
*2.A.37.2.5









Na+/H+ exchanger of 732 aas.  The exchanger is the N-terminal domain, and the C-terminal domain is in the cl00292 superfamily of adenine nucleotide alpha hydrolases.  This superfamily includes N-type ATP PPases, ATP sulphurylases, Universal Stress Response proteins and electron transfer flavoproteins (ETF). The domain forms a apha/beta/apha fold which binds to adenosine nucleotides.

Bacteria
Bacteroidetes/Chlorobi group
NHA homologue of Chlorobium limicola
*2.A.37.2.6









Putative Na+:H+ antiporter of 388 aas and 10 TMSs, Nha.

Bacteria
Proteobacteria
Nha of Bdellovibrio bacteriovorus
*2.A.37.2.7









Na+/H+ antiporter of 386 aas and 13 predicted TMSs, NapA. The 3-d structure is known (PDB# 4BWZ; 4BZ2; 4BZ3).  In the NapA structure, the core and dimerization domains are in different positions to those seen in the E. coli NhaA, and a negatively charged cavity is open to the outside. The extracellular cavity allows access to a strictly conserved aspartate residue thought to coordinate ion binding directly. To alternate access to this ion-binding site, however, requires a surprisingly large rotation of the core domain, some 20° against the dimerization interface (Lee et al. 2013).

Bacteria
Deinococcus-Thermus
NapA of Thermus thermophilus
*2.A.37.3.1









Bacterial CPA2 homologue

Bacteria
Proteobacteria
CPA2 homologue of Myxococcus xanthus
*2.A.37.3.2









Monovalent cation antiporter with CBS domain pair of 577 aas.

Bacteria
Proteobacteria
CPA protein of Pelobacter carbinolicus
*2.A.37.3.3









Putative Na+:H+ antiporter of 438 aas and 13 TMSs.

Bacteria
Spirochaetes
NHA protein of Salinispira pacifica
*2.A.37.4.1









K+:H+ antiporter, Kha1 (YJL094c)
Eukaryota
Fungi
Kha1 of Saccharomyces cerevisiae
*2.A.37.4.2









Endosome and prevacuole K+:H+ antiporter, CHX17.  Mediates potassium ion and pH homeomeostasis, thereby influencing membrane trafficking (Chanroj et al. 2011).

Eukaryota
Viridiplantae
CHX17 of Arabidopsis thaliana (AAX49545)
*2.A.37.4.3









Plasma membrane K+ uptake transporter, CHX13 (Km ≈ 150μM; expressed in roots) (Zhao et al., 2008)
Eukaryota
Viridiplantae
CHX13 of Arabidopsis thaliana (O22920)
*2.A.37.4.4









CHX08 cation:H+ antiporter (expressed in pollen; Bock et al., 2006) (most like 2.A.37.4.3; 29% identity)

Eukaryota
Viridiplantae
CHX08 of Arabidopsis thaliana (Q58P71)
*2.A.37.4.5









Cation/H(+) antiporter 23, chloroplastic (Protein CATION/H+ EXCHANGER 23) (AtCHX23)
Eukaryota
Viridiplantae
CHX23 of Arabidopsis thaliana
*2.A.37.4.6









Cation/H(+) antiporter 26 (Protein CATION/H+ EXCHANGER 26) (AtCHX26)
Eukaryota
Viridiplantae
CHX26 of Arabidopsis thaliana
*2.A.37.4.7









Cation/H(+) antiporter 1 (Protein CATION/H+ EXCHANGER 1) (AtCHX1)
Eukaryota
Viridiplantae
CHX1 of Arabidopsis thaliana
*2.A.37.4.8









Endoplasmic reticular K+/H+ antiporter, CHX20.  Maintains pH and K+ homeostasis in guard cells. Plays a critical role in osmoregulation through the control of stomates opening.  Regulates alkaline pH-sensitive growth and influences membrane trafficking (Chanroj et al. 2011).

Eukaryota
Viridiplantae
CHX20 of Arabidopsis thaliana
*2.A.37.5.1









The bidirectional K+/NH4+ transporter, AmhT (ammonium homeostasis transporter) (Fujisawa et al., 2007)
Bacteria
Firmicutes
AmhTM of Bacillus pseudoforinus
AmhT (390 aas) (O50576)
AmhM (167 aas) (O50575)
*2.A.37.5.2









The K +/H+ antiporter, YhaTU (Fujisawa et al., 2007)
Bacteria
Firmicutes
YhaTU of Bacillus subtilis
YhaT (165 aas) (O07535)
YhaU (408 aas) (O07536)