TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*2.A.24.1.1









Citrate:Na+ symporter, CitS.  Kebbel et al. 2013 presented the three-dimensional map of dimeric CitS obtained with electron crystallography. Each monomer has 13 alpha-helical transmembrane segments; six are organized in a distal helix cluster and seven in the central dimer interface domain. Based on structural analyses and comparison to VcINDY, a molecular model with assigned helices, a model with internal structural symmetry was proposed. Projections of CitS in several conformational states induced by the presence and absence of sodium and citrate as substrates were also proposed. Citrate binding induces a defined movement of alpha helices within the distal helical cluster.  Kebbel et al. 2013 proposed a substrate translocation site and conformational changes that are in agreement with the "alternating access" model.

Bacteria
Proteobacteria
CitS of Klebsiella pneumoniae
*2.A.24.2.1









L-Malate permease
Bacteria
Firmicutes
MaeP of Streptococcus bovis
*2.A.24.2.2









Malate:lactate antiporter (substrates include: S-lactate, R-lactate, S-malate and S-citramalate)
Bacteria
Firmicutes
MaeP of Lactococcus lactis
*2.A.24.2.3









Malate:Na+ symporter
Bacteria
Firmicutes
YufR of Bacillus subtilis
*2.A.24.2.4









L-malate/citrate:H+ symporter (electroneutral)
Bacteria
Firmicutes
CimH (YxkJ) of Bacillus subtilis
*2.A.24.2.5









Citrate:acetate antiporter, CitW
Bacteria
Proteobacteria
CitW of Klebsiella pneumoniae
*2.A.24.3.1









Electrogenic citrate:L-lactate exchanger, CitP or CitN (Pudlik and Lolkema 2012).

Bacteria
Firmicutes
CitN of Lactococcus lactis
*2.A.24.3.2









Citrate:lactate antiporter (substrates include: citrate, S-citramalate, S-malate, 2-hydroxylisobutyrate and R-lactate)
Bacteria
Firmicutes
CitP of Leuconostoc mesenteroides