This NCS1 subfamily includes Escherichia coli CodB (cytosine permease), and the Saccharomyces cerevisiae transporters: Fcy21p (Purine-cytosine permease), and vitamin B6 transporter Tpn1. NCS1s are essential components of salvage pathways for nucleobases and related metabolites; their known substrates include allantoin, uracil, thiamine, and nicotinamide riboside. NCS1s belong to a superfamily which also contains the solute carrier 5 family sodium/glucose transporters (SLC5s), and solute carrier 6 family neurotransmitter transporters (SLC6s).
Comment:based on the structures of Vibrio parahaemolyticus vSGLT (SLC5), Aquifex aeolicus LeuT (SLC6), and the NCS1, Microbacterium liquefaciens Mhp1, bound with Na+, functional studies of Escherichia coli PutP (SLC5) and mammalian NIS (SLC5), and mutational analysis of vSGLT
Comment:one of two Na+ binding sites in Aquifex aeolicus LeuT, where it is referred to as the Na binding site 2
Jiyao W et al.(2023). "The conserved domain database in 2023.",