Amino acid alignment of Ntl with human and <i>A.aeolicus</i> SLC6 transporters.

<p>Amino acid sequence alignment of <i>Drosophila melanogaster</i> Ntl (Ntl; NP_609135.1) with A.aeolicus Leu T_Aa (Leu; NP_214423), human homologues for Serotonin (5HT;P31645), Glycine (Gly, I57956), GABA (GABA; P30531), Dopamine (DOPA; Q01959) using Clustal W alignment [<a href="http://www.ebi.ac.uk/Tools/clustalw2/index.html" target="_blank">http://www.ebi.ac.uk/Tools/clustalw2/index.html</a>]. Strictly conserved residues are highlighted in red; α coils and β sheets are depicted as blocks and arrows respectively. Open and filled green circles represent putative cationic gates at extra and intra cellular surfaces (EL and IL) respectively. Open and filled blue triangles indicate sites that interact with sodium ions in the <i>LeuA</i> structure. Tyrosine in TM3 is a critical residue present in Ntl, which is indispensable for substrate binding and transport. Adapted from Yamashita <i>et al</i>, 2005.