TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
2.A.76.1.1









Homoserine/homoserine lactone/β-hydroxynorvaline efflux permease (probable substrate:H+ antiporter), RhtB (YigK).  Expression is under the control of the leucine-responsive protein, Lrp, and amino acids in the medium (Kutukova et al. 2005).

Bacteria
Pseudomonadota
RhtB of E. coli (P0AG34)
2.A.76.1.2









Threonine efflux permease (probable threonine:H+ antiporter), RhtC (YigJ).  Expression is under the control of the leucine-responsive protein, Lrp, and amino acids in the medium (Kutukova et al. 2005). Mutation of the rhtC gene can protect cells against toxic levels of threonine (Radi et al. 2022).

Bacteria
Pseudomonadota
RhtC (YigJ) of E. coli (P0AG38)
2.A.76.1.3









Probable amino acid exporter, YahN or YhaM, of 233 aas and 6 TMSs.  Expression is under the control of the leucine-responsive protein, Lrp, and amino acids in the medium (Kutukova et al. 2005). The yahOM operon is induced by cysteine where the cysteine sensor is the DecR/YbaO protein, and this operon is involved in L-cysteine detoxification (Shimada et al. 2016).

Bacteria
Pseudomonadota
YahN of E. coli (P75693)
2.A.76.1.4









O-aetylserine/cysteine/azaserine exporter, EamB or YfiK of 195 aas and 6 TMSs (Franke et al., 2003).  High level cell-free expression and specific labeling of EamB of E. coli has been achieved (Klammt et al. 2004). 

Bacteria
Pseudomonadota
EamB or YfiK of E. coli
2.A.76.1.5









The leucine exporter (LeuE; YeaS) (binds and probably transports L-methionine, L-histidine, L-α-amino-n-butyrate, norleucine, azaleucine, S(2-aminoethyl)-L-cysteine, 3,4-dehydro-DL-proline, L-alanine, and both D- and L-valine) (Kutukova et al., 2005; Hori et al., 2011; Radi et al. 2022).  Expression is under the control of the leucine-responsive protein, Lrp, and amino acids in the medium (Kutukova et al. 2005). Mutation of the leuE gene allows tolerance to high levels of histidine, presumably by allowing histidine efflux (Radi et al. 2022).

Bacteria
Pseudomonadota
LeuE of E. coli (P76249)
2.A.76.1.6









The RhtB family member, RSP_2720

Bacteria
Pseudomonadota
RSP_2070 of Rhodobacter sphaeroides (Q3J2V9)
2.A.76.1.7









Putative amino acid exporter of 208 aas; RhtB family member; similar to 2.A.76.1.5.

Bacteria
Bacillota
RhtB family member of Bacillus subtilis
2.A.76.1.8









Putative amino acid efflux porter of 210 aas, YrhP.  Most similar to 2.A.76.1.5 of the characterized proteins in TCDB.

Bacteria
Bacillota
YrhP of Bacillus subtilis
2.A.76.1.9









Exporter for L-homoserine, L-serine, and L-homoserine lactone as well as the quorum-sensing pimaricin-inducer PI-factor (2,3-diamino-2,3-bis(hydroxymethyl)-1,4-butanediol), PimT (Vicente et al. 2009).

Bacteria
Actinomycetota
PimT of Streptomyces natalensis
2.A.76.1.10









RhtB family porter of 210 aas and 6 TMSs.  Based on homology, may export serine, threonine, homoserine and/or homoserine lactones.  Possibly regulated by a LysR transcription factor.  The gene maps adjacent to a probable heterodimeric DMT superfamily transporter (2.A.7.21.5).

Bacteria
Pseudomonadota
RhtB family homologue of Klebsiella oxytoca
2.A.76.1.11









Amino acid exporter of 210 aas and 6 TMSs, MrsC.  Encoded by the mrsC gene in an operon for the biosynthesis of the toxic amino acid analogue, 3-methyarginine, the likely substrate (Braun et al. 2010).  The epiphytic Pseudomonas syringae strain which produces and excretes 3-methyarginine does so to compete with pathogenic strains of P. syringae for which 3-methyarginine is toxic.

Bacteria
Pseudomonadota
MrsC of Pseudomonas syringae
2.A.76.1.12









Uncharacterized amino acid transporter of 207 aas and 6 TMSs.

Bacteria
Candidatus Wolfebacteria
UP of Candidatus Wolfebacteria bacterium
2.A.76.1.13









LysE superfamily member of 220 aas and 6 TMSs in a 3 + 3 arrangement

Archaea
Candidatus Lokiarchaeota
LysE member of Lokiarchaeum sp. GC14_75 (from a marine sediment metagenome)
2.A.76.2.1









Potential coronamic acid exporter of 236 aas and 5 TMSs.  Coronamic acid (CMA), an ethylcyclopropyl amino acid derived from isoleucine, functions as an intermediate in the biosynthesis of coronatine, a chlorosis-inducing phytotoxin produced by Pseudomonas syringae pv. glycinea PG4180. The DNA required for CMA biosynthesisincludes three distinct open reading frames (ORFs) which share a common orientation for transcription.  Two ORFs in the operon include CmaT, a thioesterase and CmaU, a potential exporter (Ullrich and Bender 1994).

Bacteria
Pseudomonadota
CmaU of Pseudomonas syringae
2.A.76.2.2









CmaU of 203 aas and 5 or 6 TMSs.  This protein resembles 2.A.76.2.1; one or the other may be an incomplete or inaccurate sequence.

Bacteria
Pseudomonadota
CmaU of Pseudomonas syringae
2.A.76.2.3









CmaU homologue of 203 aas and 6 TMSs.

Bacteria
Pseudomonadota
CmaU of Achromobacter xylosoxidans
2.A.76.3.1









Uncharacterized probable amino acid exporter of 230 aas and 6 TMSs.

Bacteria
Bacteroidota
UP of Croceibacter atlanticus