TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*4.A.2.1.1









Fructose porter (FruAB) (fructose-1-P forming)
Bacteria
Proteobacteria
Fructose IIB'BC-IIAMH complex of E. coli
*4.A.2.1.2









Mannitol porter (MtlA) (mannitol-1-P forming), the mannitol IICBA complex.  The enzyme-transporter has been alterred genetically, sequenced, purified, reconstituted and characterized (Jacobson et al. 1983, Leonard and Saier 1983, Lee and Saier 1983, Manayan et al. 1988). Intramolecular phosphoryl transfer between the A and B domains of IIMtl is rate-limited by chemistry and not by the rate of formation or dissociation of a stereospecific complex in which the active sites are optimally apposed (Suh et al. 2007). Substrates, in addition to D-mannitol, include D-glucitol (D-sorbitol), D-2-amino-2-deoxymannitol, D-2-deoxymannitol and D-arabitol (D-arabinitol) (Jacobson et al. 1983).

Bacteria
Proteobacteria
Mannitol IICBA complex of E. coli
*4.A.2.1.3









The 2-O-α-mannosyl D-glycerate porter (2-O-α-mannosyl D-glycerate-6-P forming), MngA (HrsA) (Sampaio et al., 2004).  The phosphorylated product is hydrolyzed to manose-6-P and glycerate by MngB, an α-mannosidase.

Bacteria
Proteobacteria
2-O-α-mannosyl D-glycerate IIABC complex of E. coli
*4.A.2.1.4









The fructose porter, FruA (fructose-1-P forming IIABC) (Delobbe et al. 1975) FruA is 39% identical to 4.A.2.1.1). fructose can be metabolized to Fru-1-P via this system as well as Fru-6-P by another PTS system (Gay and Delobbe 1977).

Bacteria
Firmicutes
Fructose IIABC of Bacillus subtilis (gi2633811)
*4.A.2.1.5









The mannitol porter (MtlA) (mannitol-1-P forming), MtlAF.  The system is encoded by the mannitol catabolic operon, mtlAFD, and is regulated by the transcription factor, MtlR (Joyet et al. 2015). MtlR contains an N-terminal helix-turn-helix motif followed by an Mga-like domain, two PTS regulatory domains (PRDs), an Enzyme IIBGat-like domain and an Enzyme IIAMtl-like domain, the last four of which can be phosphorylated by the PTS.  MtlR proteins are also found in Geobacillus stearothermophilus and Lactobacillus casei, but the mechanisms of their action are different (Joyet et al. 2015).  The dephosphorlyated form of the protein activates transcription (Heravi and Altenbuchner 2014).

Bacteria
Firmicutes
Mannitol IICB/A (MtlA/F) of Bacillus subtilis (P42956)
*4.A.2.1.6









The mannose porter (ManP) (37% identical to 4.A.2.1.1). It is encoded in an operon with 3 genes:  manP-manA-yjdD, where manP codes for the IIBCA mannose transporter, manA codes for a mannose-6-P isomerase and YjdD  codes for a 5-formyltetrahydrofolate cyclo-ligase, characterized in B. anthrasis.  Expression of the operon is regulated by ManP and ManR, an activator, in response to external mannose (Sun and Altenbuchner 2010). 

Bacteria
Firmicutes
Mannose IIBCA of Bacillus subtilis (gi2633555)
*4.A.2.1.7









The fructose inducible fructose/xylitol porter, FruI (Benchabane et al., 2002; Tanzer et al., 2006; Wen et al., 2001)
Bacteria
Firmicutes
FruI (IIABC) of Streptococcus mutans (DAA01814)
*4.A.2.1.8









The constitutive fructose porter FruC/FruD (Benchabane et al., 2002; Tanzer et al., 2006; Wen et al., 2001)
Bacteria
Firmicutes
FruC/D (IIBC/IIA) of Streptococcus mutans
FruC (IIBC) (AAN57895)
FruD (IIA) (DAA01808)
*4.A.2.1.9









The FrzABC PTS putative transporter (promotes bacterial fitness under stress conditions and promotes fimbrial (fim) gene expression indirectly (Rouquet et al., 2009). Might transport D-tagatose, D-psicose and/or D-sorbose, or a disaccharide of these (Rouquet et al. 2009); involved in environmental sensing, host adaptation and virulence (Patron et al. 2015).

Bacteria
Proteobacteria
FrzABC of E. coli
FrzA (IIA) (Q1R4S9)
FrzB (IIB) (Q8FC73)
FrzC (IIC) (Q1R4T1)
*4.A.2.1.10









The FrwABCD putative transporter of unknown function. FruA is a 3-domain multiphosphoryl transfer protein: EIAni-HPr-IIAFru (Reizer et al., 1995).

Bacteria
Proteobacteria
FrwABCD of E. coli
FrwA (IIA) (P32670)
FrwB (IIB) (P69816)
FrwC (IIC) (P32672)
FrwD (IIB) (P32676)
*4.A.2.1.11









The FryABC putative transporter of unknown function.  FryA is a 3-domain multiphosphoryl transfer protein: EI-HPr-IIAFru (Reizer et al., 1995).

Bacteria
Proteobacteria
FryABC of E. coli
FryA (IIA) (P77439)
FryB (IIB) (P69808)
FryC (IIC) (P77579)
*4.A.2.1.12









The mannitol/glucitol transporter, MtlA (IICBAMtl) (Kumar et al., 2011)

Bacteria
Proteobacteria
MtlA (IICBA) of Vibrio cholerae (Q9KKQ7)
*4.A.2.1.13









The fructose-specific PTS Enzyme IIABC FruA (Araki et al., 2011).

Bacteria
Actinobacteria
FruA of Rhodococcus jostii (Q0S1N2)
*4.A.2.1.14









Fructose Enzyme II complex (IIAFru - IIBFru - IICFru) (based on homology)

Archaea
Euryarchaeota
IIABCFru of Haloterrigena turkmenica
IIA (D2RXA7)
IIB (D2RXA4)
IIC (D2RXA8) 
*4.A.2.1.15









Fructose-specific PTS, PtfABC (functions with 8.A.7.1.4 and 8.A.8.1.4; Pickl et al., 2012).  The transcriptional regulation of the fructose PTS in the very similar organism, Haloferax mediterranei, has shown that GlpR is a transcriptional activator (Cai et al. 2014).

Archaea
Euryarchaeota
Fructose Enzyme II, PtfABC (IIABC) complex of Haloferax volcanii 
PtfA (IIA) (D4GYE1)
PtfB (IIB) (D4GYE4)
PtfC (IIC) (D4GYE5) 
*4.A.2.1.16









Fructose-specific Enzyme IIABC (Gaurivaud et al. 2000).

Bacteria
Tenericutes
Fructose IIABC of Spiroplasma citri
*4.A.2.1.17









Fructose-specific PTS permease, FruIIBC/FruI-HPr-IIA (Johnson et al. 2008).

Bacteria
Proteobacteria
FruIIBC/FruI-HPr-IIA of Pseudomonas aeruginosa
FruIIBC (Q9HY57)
FruI-HPr-IIA (Q9HY55)
*4.A.2.1.18









Fructose PTS Enzyme IIBC, FruA.  The gene encoding the IIA protein is an inactive pseudogene, and fructose appears to be phosphorylated by an ATP-dependent mechanism (Lee et al. 2012).

Bacteria
Deinococcus-Thermus
FruA of Deinococcus radiodurans
*4.A.2.1.19









The tagatose-specific PTS transporter/kinase, TagIIA-TPr/TagIIB'BC (tagatose-1-P forming) (Shakeri-Garakani et al. 2004).  TagIIA-TPr is a fusion of a IIA domain fused N-terminal to an HPr domain.  TagIIB'BC has and inactive IIB' domain fused N-terminal to the active C-terminal IIBC domains.  This arrangement resembles that for the E. coli fructose Enzyme II complex.

Bacteria
Proteobacteria
Tag PTS of Klebsiella pneumoniae
*4.A.2.1.20









Chromosomal fructose Enzyme IIABC (Fru1) of 654 aas; in an operon with fructose-1-P kinase (Patron et al. 2015).

Bacteria
Firmicutes
Fru1 of Streptococcus agalactiae
*4.A.2.1.21









Putative fructose Enzyme II complex, Fru3; IIA (148 aas)/IIBC (464 aas) (Richards et al. 2011).

Bacteria
Firmicutes
IIA/IIBC of Streptococcus agalactiae
*4.A.2.1.22









D-allose/D-ribose transporting Enzyme II complex (Fru2; IIA/IIB/IIC) (Patron et al. 2017). This system is similar to Frz of E. coli (TC#4.A.2.1.9) which is involved in environmental sensing, host adaptation and virulence (Patron et al. 2015).  The regulatory mechanism has been studied (Patron et al. 2017).

Bacteria
Firmicutes
D-Ribose and D-allose transporting Enzyme II complex of Streptococcus agalactiae
IIA, 149 aas
IIB, 103 aas
IIC, 367 aas
*4.A.2.1.23









The tagatose-1-P-forming tagatose phosphorylating Enzyme IIA/IIBC, TagM/L (Van der Heiden et al. 2015). The product is phosphorylated by tagatose-1-P kinase (TagK), and then cleaved by tagatose-1,6-bisphosphate aldolase (GatY).

Bacteria
Firmicutes
TagLK of Bacillus licheniformis
TagL (IIBCTag), 466 aas
TagM (IIATag), 152 aas
*4.A.2.1.24









Cryptic mannitol permease, CmtA (IICB; 462 aas; 9 - 10 TMSs) - CmtB (IIA; 147 aas.)

Bacteria
Proteobacteria
CmtA-CmtB of E. coli
*4.A.2.1.25









Fructose-like PTS Enzyme II complex, FrvA (IIA of 148 aas) - FrvB (IIBC of 483 aas and 9 predicted TMSs) (Reizer et al. 1994).

Bacteria
Proteobacteria
FrvIIa/IIBC of E. coli
*4.A.2.1.26









Fructose-specific Enzyme I-HPr-Enzyme IIABC complex, all encoded within a single operon with genes in the order: ptsC (IIC), ptsA (IIA), ptsH (HPr), ptsI (Enzyme I) and ptsB (IIB) (Comas et al. 2008).

Archaea
Euryarchaeota
Fructose Enzyme II complex including EI and HPr of Haloarcula marismortui