TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*2.A.15.1.1









Glycine betaine:Na+ symporter (also transports dimethylsulfonioacetate and dimethylsulfoniopropionate)

Bacteria
Firmicutes
OpuD of Bacillus subtilis
*2.A.15.1.2









Ectosine/glycine betaine/proline:Na+ symporter

Bacteria
Actinobacteria
EctP of Corynebacterium glutamicum
*2.A.15.1.3









Low affinity (0.9 mM), high efficiency, choline/glycine betaine:H+ symporter, BetT (Chen and Beattie, 2007)

Bacteria
Proteobacteria
BetT of Pseudomonas syringae (Q4ZLW8)
*2.A.15.1.4









The high-affinity, proton- or sodium-driven, secondary symporter, BetT.  The cytoplasmic C-terminal domain of plays a role in the regulation of BetT activity; C-terminal truncations cause BetT to be permanently locked in a low-transport-activity mode. (Tøndervik and Strøm 2007).

Bacteria
Proteobacteria
BetT of E. coli (P0ABC9)
*2.A.15.1.5









Glycine-betaine/proline-betaine:Na+ symporter, BetS

Bacteria
Proteobacteria
BetS of Sinorhizobium meliloti (Q92WM0)
*2.A.15.1.6









The glycine betaine, dimethylsulfoniopropionate:Na+ symporter (Ziegler et al., 2010).

Bacteria
Proteobacteria
Dddt of Psyohrobacter sp. J466 (D0U567)
*2.A.15.1.7









The ectoine/glycine:Na+ symporter, LcoP (Ziegler et al., 2010).

Bacteria
Actinobacteria
LcoP of Corynebacterium glutamicum (Q8NN75)
*2.A.15.1.8









The ectoine/hydroxyectoine:Na+ symporter, EctT (Ziegler et al., 2010).

Bacteria
Firmicutes
EctT of Virgibacillus pantothenticus (Q93AK1)
*2.A.15.1.9









High affinity glycine betaine uptake system

Bacteria
Proteobacteria
Glycine betaine transporter of Acinetobacter baylyi (Q6F754)
*2.A.15.1.10









Glycine betaine transporter, BetP. The x-ray structure is known (3PO3; 2WIT; Ressl et al., 2009). Regulatory crosstalk in the trimeric BetP has been reported (Gärtner et al., 2011). An extracellular K+ -dependent interaction site modulates betaine-binding (Ge et al., 2011). The porter is trimeric and exhibits structural asymmetry (Tsai et al., 2011). The C-terminal domain is involved in osmosensing and is trimeric like wild-type BetP.  The two Na+ binding sites are between TMSs 1 and 8 in the first and second 5 TMS repeats, and between the equivalent TMSs 6 and 3 in the second and first repeats, respectively (Khafizov et al. 2012). interdependent binding of betaine and two sodium ions is observed during the coupling process. All three sites undergo progressive reshaping and dehydration during the alternating-access cycle, with the most optimal coordination of all substrates found in the closed state (Perez et al. 2014). BetP is active and regulated only when negatively charged lipids such as phosphatidyl glycerol are present, and the mechanism has been discussed (Güler et al. 2016).  The K+-sensing C-terminal domain results in K+-dependent cooperative betaine-binding (Ge et al. 2011).

Bacteria
Actinobacteria
BetP of Corynebacterium glutamicum (P54582)
*2.A.15.1.11









Glycine betaine transporter BetL (Glycine betaine-Na(+) symporter)
Bacteria
Firmicutes
BetL of Listeria monocytogenes
*2.A.15.2.1









Carnitine:γ-butyrobetaine antiporter.  The x-ray structure is known at 3.5 Å resolution (Schulze et al., 2010).  The structure reveals a homotrimer where each protomer has 12 TMSs with 4 L-carnitine molecules outlining the pathway.  There is a central binding site and another in the intracellular vestibule (Tang et al. 2010).

Bacteria
Proteobacteria
CaiT of E. coli (P31553)
*2.A.15.2.2









The L-carnitine:γ-butyrobetaine antiporter, CaiT.  The x-ray structure is known at 2.3 Å resolution (Schulze et al., 2010).

 

Bacteria
Proteobacteria
CaiT of Proteus mirabilis (B4EY22)  
*2.A.15.2.3









Uncharacterized transporter, YeaV

Bacteria
Proteobacteria
YeaV of Escherichia coli O157:H7