Background
LeuTAa is a bacterial orthologue of mammalian Solute Carrier Class 6 (SLC6) neurotransmitter transporters from Aquifex aeolicus which transports leucine and alanine. SLC6 transporters are of great pharmacological interests because of their crucial role in neurotransmitter clearance. These proteins are also targets of many clinically relevant drugs. The crystal structure of LeuTAa has been resolved at atomic resolution of ~1.5 Å. Although LeuT has a low overall sequence identity of about 20–25% to SLC6 members, the grade of conservation reaches around 55% in functionally critical transmembrane domains 1, 3, 6 and 8. For this very reason we are using LeuTAa as a good structural paradigm to explore the structural/functional information about SLC6-family members.