TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
4.A.7.1.1









The L-ascorbate transporting and phosphorylating group translocator, SgaTBA or UlaCBA (SgaT = UlaA = YjfS; SgaB = UlaB = YjfT; SgaA = UlaC = PtxA = YjfU) (Hvorup et al., 2003; Zhang et al., 2003). Two conformations of the 3-d structure have been determined at 1.65 and 2.35 Å resolution, respectively (Luo et al., 2015). UlaA (SgaT) forms a homodimer with a novel fold. Each UlaA protomer consists of 11 TMSs arranged into a 'V-motif' domain and a 'core' domain. The V motifs form the interface between the two protomers, and the core-domain residues coordinate vitamin C. Alternating access of the substrate to the two sides of the cell membrane may be achieved through rigid-body rotation of the core relative to the V motif (Luo et al., 2015; Zhang et al., 2003). This structure does not resemble the ChbC structure (TC# 4.A.3.2.8).

Bacteria
Proteobacteria
L-ascorbate (L-Asc) IIC-IIB-IIA complex of E. coli
IIC (SgaT)
IIB (SgaB)
IIA (SgaA)
4.A.7.1.2









Virulence-associate PTS, VpeABC (substrate unknown).  Essential for virulence and normal colonization of the kidney and intestine by uropathogneic E. coli (UPEC) (Martinez-Jéhanne et al. 2012).

Bacteria
Proteobacteria
VpeABC of E. coli AL511
4.A.7.1.3









Putative Enzyme IIC specific for ascorbate of 410 aas

Bacteria
Firmicutes
IICasc of Clostridium carboxidivorans
4.A.7.1.4









Uncharacterized protein of 420 aas; possibly a IIC or IICB PTS protein (based on homology); SgaT/UlaA

Bacteria
Proteobacteria
UlaA/SgaT of Klebsiella pneumoniae
4.A.7.1.5









Uncharacterized protein of 424 aas and 12 TMSs

Bacteria
Firmicutes
UP of Turicibacter sanguinis
4.A.7.1.6









The PTS ascorbate transporter subunits IIBC (596 aas and 11 TMSs) and IIA (155 aas).The 3-d structure has been determined at high resolution of the inward open configuration, showing that ascorbate translocation can be achieved by a rigid-body movement of the substrate-binding core domain relative to the V motif domain, which brings along the transmembrane helices TM2 and TM7 of the V motif domain to undergo a winding at the pivotal positions (Luo et al. 2018). This completes the picture of the transport cycle of the ascorbate superfamily of membrane-spanning EIIC components of the PTS.

Bacteria
Proteobacteria
Ascorbate transporter of Pasteurella multocida