Table 1. Summary of nine TOG Superfamily family members.
The family number, name, abbreviation, TC number, number of TMSs, normal protein size range in numbers of amino acyl residues, dominant topology, TMS gain or loss, organismal distribution and Pfam id designation are presented. Minor topologies, represented in a minority of family members, are listed in small numbers in parentheses in column 7. Putative topological transitions are described in footnotes 1–4.
| Family # | Family Name | Family Abb’n | TC # | # TMSs | Common Protein Size Range | Topology | TMS Gain or Loss (Primary) | Organismal Distribution | Pfam id |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Ion-Translocating Microbial Rhodopsin | MR | 3.E.1 | 7 | 250–350 | 3 + 1 + 3 | 7 arose from 8 by loss of the N-terminal TMS. | Archaea, Bacteria, Eukaryota | Bac_rhodopsin |
| 2 | Sweet1 | Sweet | 9.A.58 | 3 or 7 | 200–290 | 3 + 1 + 3 (3) | 7 arose from 8 by loss of the N-terminal TMS. | Archaea, Bacteria, Eukaryota | MtN3_slv |
| 3 | Nicotinamide Ribonucleotide Uptake Permease | PnuC | 4.B.1 | 7 or 8 | 210–270 | 3 + 1 + 3 (4 + 4) | 7 arose from 8 by loss of the N-terminal TMS. | Bacteria, Eukaryota | NMN_transporter, AAA_28 |
| 4 | 4-Toluene Sulfonate Uptake Permease2 | TSUP | 2.A.102 | 7–9 | 250–600 | 4 + 4 (3 + 1 + 3; 1 + 4 + 4) | 8 arose from internal duplication of 4 TMSs | Archaea, Bacteria, Eukaryota | TauE |
| 5 | Ni2+-Co2+ Transporter3 | NiCoT | 2.A.52 | 6–8 | 300–380 | 4 + 4 (3 + 1 + 3; 2 + 1 + 1 + 2) | 8 arose from internal duplication of 4 TMSs | Archaea, Bacteria, Eukaryota | NicO |
| 6 | Organic Solute Transporter | OST | 2.A.82 | 7 | 180–400 | 3 + 1 + 3 | 7 arose from 8 by loss of the N-terminal TMS. | Eukaryota | Solute_trans_a |
| 7 | Phosphate:Na+ Symporter4 | PNaS | 2.A.58 | 8 or 9 | 500–700 | 4 + 4 (4 + 4 + 1) | 8 arose from internal duplication of 4 TMSs | Bacteria, Eukaryota | Na_Pi_cotrans |
| 8 | Lysosomal Cystine Transporter | LCT | 2.A.43 | 7 | 300–400 | 3 + 1 + 3 | 7 arose from 8 by loss of the N-terminal TMS. | Eukaryota | PQ-loop |
| 9 | G-protein Coupled Receptor | GPCR | 9.A.14 | 7 | 300–1200 | 3 + 1 + 3 | 7 arose from 8 by loss of the N-terminal TMS 1. | Eukaryota | 7tm_1, 7tm_2, 7_tm3 |
1
3 arose from 4 TMSs by loss of one TMS.
2
7 arose from 8 by loss of the N-terminal TMS; 9 arose from 8 by gain of an N-terminal TMS.
3
7 arose from 8 by loss of the 8th (C-terminal) TMS; 6 arose from 7 by loss of the N-terminal TMS.
4
9 arose from 8 by gain of a C-terminal TMS.