TCID | Name | Domain | Kingdom/Phylum | Protein(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. The loop between TMSs VIII and IX folds into an amphipathic surface helix (Sobczak and Lolkema 2005). | Bacteria |
Pseudomonadota | CitS of Klebsiella pneumoniae |
2.A.24.1.2 | CitS or CitT of Salmonella enterica (typhi) of 446 aas with 11 or 12 TMSs. It shows narrow substrate specificity and is very specific, transporting only citrate and to a low extent citromalate (Bandell et al. 1997). Also Na+ can be replaced by Li+, but only at very high concentrations. | Bacteria |
Pseudomonadati, Pseudomonadota | CitS of Salmonella enterica |
2.A.24.2.1 | L-Malate permease | Bacteria |
Bacillota | MaeP of Streptococcus bovis |
2.A.24.2.2 | Malate:lactate antiporter (substrates include: S-lactate, R-lactate, S-malate and S-citramalate) | Bacteria |
Bacillota | MaeP of Lactococcus lactis |
2.A.24.2.3 | Malate:Na+ symporter | Bacteria |
Bacillota | YufR of Bacillus subtilis |
2.A.24.2.4 | L-malate/citrate:H+ symporter (electroneutral) | Bacteria |
Bacillota | CimH (YxkJ) of Bacillus subtilis |
2.A.24.2.5 | Citrate:acetate antiporter, CitW | Bacteria |
Pseudomonadota | CitW of Klebsiella pneumoniae |
2.A.24.3.1 | Electrogenic citrate:L-lactate exchanger, CitP or CitN (Pudlik and Lolkema 2012). | Bacteria |
Bacillota | 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 |
Bacillota | CitP of Leuconostoc mesenteroides |