InterPro domain: IPR044739

The plant Nitrate transporter/Peptide transporter (NRT1/PTR) family (NPF) is related to the POT (proton-coupled oligopeptide transporter), Peptide transporter (PepT/PTR), or Solute Carrier 15 (SLC15) family in animals [ 1 , 2 ]. In contrast to related animal and bacterial counterparts, the plant proteins transport a wide variety of substrates including nitrate, peptides, amino acids, dicarboxylates, glucosinolates, as well as the plant hormones indole-3-acetic acid (IAA) and abscisic acid (ABA). A study identified eight subfamilies within this family, named NPF1-NPF8 [ 3 ].

This entry represents NPF5, which includes Arabidopsis thaliana PTR3 (AtPTR3, now named AtNPF5.2), a wound-induced peptide transporter that is necessary for defense against virulent bacterial pathogens [ 4 , 5 ]. NPF5 belongs to the Major Facilitator Superfamily (MFS) of membrane transport proteins, which are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement [ 6 ].

1. Structural basis for polyspecificity in the POT family of proton-coupled oligopeptide transporters. EMBO Rep 15, 886-93
2. Molecular insights into proton coupled peptide transport in the PTR family of oligopeptide transporters. Biochim Biophys Acta 1850, 488-99
3. A unified nomenclature of NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER family members in plants. Trends Plant Sci 19, 5-9
4. AtPTR3, a wound-induced peptide transporter needed for defence against virulent bacterial pathogens in Arabidopsis. Planta 225, 1431-45
5. Structural and functional characterization of AtPTR3, a stress-induced peptide transporter of Arabidopsis. J Mol Model 11, 226-36
6. Evolutionary mix-and-match with MFS transporters. Proc. Natl. Acad. Sci. U.S.A. 110, 5870-4