title: YddG from Escherichia coli promotes export of aromatic amino acids.
abstract: The inner membrane protein YddG of Escherichia coli is a homologue of the known amino acid exporters RhtA and YdeD. It was found that the yddG gene overexpression conferred resistance upon E. coli cells to the inhibiting concentrations of l-phenylalanine and aromatic amino acid analogues, dl-p-fluorophenylalanine, dl-o-fluorophenylalanine and dl-5-fluorotryptophan. In addition, yddG overexpression enhanced the production of l-phenylalanine, l-tyrosine or l-tryptophan by the respective E. coli-producing strains. On the other hand, the inactivation of yddG decreased the aromatic amino acid accumulation by these strains. The cells of the E. colil-phenylalanine-producing strain containing overexpressed yddG accumulated less l-phenylalanine inside and exported the amino acid at a higher rate than the cells of the isogenic strain containing wild-type yddG. Taken together, these results indicate that YddG functions as an aromatic amino acid exporter.
authors.affiliation: Ajinomoto-Genetika Research Institute, Moscow, Russian Federation.
authors.forename: Vera
authors.initials: V
authors.lastname: Doroshenko
authors.forename: Larisa
authors.initials: L
authors.lastname: Airich
authors.forename: Maria
authors.initials: M
authors.lastname: Vitushkina
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kolokolova
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Livshits
authors.forename: Sergey
authors.initials: S
authors.lastname: Mashko
mesh_terms: D024322:Amino Acids, Aromatic / Q000378:metabolism*; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport