Species	Reference gene ID	Possible function	Papers / DOI
Arabidopsis	At2g03530	Proton-coupled transporter that transports a wide spectrum of oxo derivatives of heterocyclic nitrogen compounds, including allantoin, uric acid and xanthine, but not adenine.	UPS1 and UPS2 from Arabidopsis mediate high affinity transport of uracil and 5-fluorouracil.; 2004; DOI: 10.1074/jbc.m405433200; PMID: 15308648; https://pubmed.ncbi.nlm.nih.gov/15308648/
Arabidopsis	At2g03590	Proton-coupled transporter that transports a wide spectrum of oxo derivatives of heterocyclic nitrogen compounds, including allantoin, uric acid and xanthine, but not adenine.	A novel superfamily of transporters for allantoin and other oxo derivatives of nitrogen heterocyclic compounds in Arabidopsis.; 2002; DOI: 10.1105/tpc.010458; PMID: 11971139; https://pubmed.ncbi.nlm.nih.gov/11971139/ | UPS1 and UPS2 from Arabidopsis mediate high affinity transport of uracil and 5-fluorouracil.; 2004; DOI: 10.1074/jbc.m405433200; PMID: 15308648; https://pubmed.ncbi.nlm.nih.gov/15308648/ | Heterologous expression of a plant uracil transporter in yeast: improvement of plasma membrane targeting in mutants of the Rsp5p ubiquitin protein ligase.; 2006; DOI: 10.1002/biot.200500034; PMID: 16897711; https://pubmed.ncbi.nlm.nih.gov/16897711/
Arabidopsis	At2g03520	Proton-coupled transporter that transports a wide spectrum of oxo derivatives of heterocyclic nitrogen compounds.	No verified direct reference in this release
Arabidopsis	At1g26440	Proton-coupled transporter that transports a wide spectrum of oxo derivatives of heterocyclic nitrogen compounds, including allantoin, uric acid and xanthine, but not adenine.	Comparative studies on Ureide Permeases in Arabidopsis thaliana and analysis of two alternative splice variants of AtUPS5.; 2006; DOI: 10.1007/s00425-006-0315-z; PMID: 16738859; https://pubmed.ncbi.nlm.nih.gov/16738859/