Homology modeling of the serotonin transporter: Insights into the primary escitalopram-binding site

The serotonin transporter (SERT) is one of the neuro transmitter transporters that plays a critical role in the regulation of endogenous amine concentrations and therefore is an important target for therapeutic agents affecting the central nervous system. The recently published, high resolution X-ray structure of the closely related amino acid transporter, Aquifex aeolicus leucine transporter (LeuT), provides on opportunity to develop a three-dimensional model of the structure of SERT We present herein a homology model of SERT using LeuT as the template and containing escitoloprom as a bound ligand. Our model explains selectivities known from mutational studies and varying ligand data, which are discussed and illustrated in the paper.