An examination of the integral membrane constituents of ABC transporters revealed INK1197 that Sco has nearly three times as many ABC membrane proteins as does Mxa (202 versus 72). This difference, as well as the nearly four-fold greater number of MFS carriers in Sco, provides the majority of differences in the numbers of membrane transport proteins found within these two organisms. Table 9 lists the families, numbers per family, and probable substrates of the ABC uptake proteins found in these two organisms. ABC porters include 3 independently evolving protein types, ABC1, ABC2 and ABC3, and all three types are represented in both Sco and Mxa [28]. The
most striking difference
between Sco and Mxa is the large number of sugar porters in Sco (85) as compared with Mxa (6). However, Sco has 12 amino acid and 17 peptide ABC transport proteins while Mxa has only 4 and 3, respectively. It seems that while Mxa primarily uses secondary carriers of the OPT family for peptide uptake, Sco primarily uses transporters of the ABC superfamily. Table 9 ABC uptake porters in Sco and Mxa ABC Family Sco Mxa 1 Carbohydrate Uptake Transporter-1 (CUT1) Family Carbohydrates 75 4 2 Carbohydrate Uptake Transporter-2 (CUT2) Family Carbohydrates 10 2 3 Polar Amino Acid Uptake Transporter www.selleckchem.com/products/a-1155463.html (PAAT) Family Polar amino acids 5 1 4 Hydrophobic Amino Acid Uptake Transporter (HAAT) Family Non-polar amino acids 6 2 5 Peptide/Opine/Nickel Uptake Transporter (PepT) Family Peptides, oligosaccharides 17 3 6 Sulfate/Tungstate Glutathione peroxidase Uptake Transporter (SulT) Family Sulfate 1 1 7 Phosphate Uptake Transporter (PhoT) Family Phosphate 3 2 8 Molybdate Uptake Transporter (MolT) Family Molybdate 1 1 10 Ferric Iron Uptake Transporter (FeT) Family Iron 2 11 Polyamine/Opine/Phosphonate Uptake Transporter (POPT) Family
Polyamines/opines/phosphonates 3 12 Quaternary Amine Uptake Transporter (QAT) Family Quaternary/amines 6 2 14 Iron Chelate Uptake Transporter (FeCT) Family Iron chelates 8 4 15 Manganese/Zinc/Iron Chelate Uptake Transporter (MZT) Family Mn2+/Zn2+/Fe2+ chelates 2 1 17 Taurine Uptake Transporter (TauT) Family Taurine 2 2 18 Cobalt Uptake Transporter (CoT) Family Cobalt (Co2+) 2 20 Brachyspira Iron Transporter (BIT) Family Iron 1 21 Siderophore-Fe3+ Uptake Transporter (SIUT) Family Siderophore-iron 2 2 23 Nickel/Cobalt Uptake Transporter (NiCoT) Family Nickel; cobalt 2 24 Methionine Uptake Transporter (MUT) Family Methionine 1 1 27 γ-Hexachlorocyclohexane (HCH) Family γ-hexachlorohexane/cholesterol 2 4 32 Cobalamin Precursor (B12-P) Family Vitamin B12 precursors 2 Numbers of integral membrane ABC uptake proteins in Sco and Mxa arranged by family.