Table 22.

Transporter families including nontransporter homologs

FamilyTC no.OccurrenceNontransporter homologTC no.Organism
MFS2.A.1BAELow-glucose Tx sensor, Snf3p2.A.1.1.18S. cerevisiae
High-glucose Tx sensor, Rgt2p2.A.1.1.19S. cerevisiae
Glucose 6-phosphate Tx sensor, UhpC2.A.1.4.4E. coli
APC2.A.3BAELeucine Tx sensor, Ssy1p2.A.3.1.20S. cerevisiae
RND2.A.6BAE“Patched” polarity Tx receptor2.A.6.6.2D. melanogaster
SREBP cleavage-activating protein, SCAP2.A.6.6.4C. griseus
HMG-CoA reductase2.A.6.6.5H. sapiens
AMT2.A.49BAENH4+transporter and sensor, Mep2p2.A.49.3.2S. cerevisiae
BR3.E.1AESensory rhodopsin3.E.1.3.1H. salinarum
Heat and shock protein, HSP303.E.1.4.1S. cerevisiae
ABC3.A.1BAESUR1 sulfonylurea receptor; regulator of ATP-sensitive K+channels3.A.1.68.4H. sapiens
Cytoplasmic and periplasmic protein homologs function in other capacities (Tx, receptors, energizers)Bacteria; animals
PTS4.A.1–4.A.6BsacX transcriptional regulator4.A.1.2.1Bacillus subtilis
Permeases are generally sugar kinases, but cytoplasmic proteins may function in regulationBacteria