Molecular Cloning of an Amino Acid Permease Gene and Structural Characterization of the Protein in Common Bean (Phaseolus vulgaris L.)

Plants synthesize amino acids by collateral metabolic pathways using primary elements carbon and oxygen from air, hydrogen from water in soil and nitrogen from soil. Following synthesis, amino acids are immediately used for metabolism, transient storage or transported to the phloem. Different families of transporters have been identified for import of amino acids into plant cells. The first identified amino acid transporter, amino acid permease 1 (AAP1) in Arabidopsis belongs to a family of eight members and transports acidic, neutral, and basic amino acids. Legumes fix atmospheric nitrogen through a symbiotic relationship with root nodules bacteria. Following fixation, nitrogen is reduced to amino acids and is exported via different amino acid transporters. However, information is lacking about the structure of these important classes of amino acid transporter proteins in plant. We have amplified AAP from Phaseolus vulgaris, an economically important leguminous plant grown all over the world, and sequenced. The sequence has been characterized in silico and a three-dimensional structure of AAP has been predicted and validated. The information obtained not only enhances the knowledge about the structure of an amino acid permease gene in P. vulgaris, but will also help in designing protein-ligand studies using this protein as well.