YddG from Escherichia coli promotes export of aromatic amino acids.
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.
Doroshenko
Vera
V
Ajinomoto-Genetika Research Institute, Moscow, Russian Federation.
Airich
Larisa
L
Vitushkina
Maria
M
Kolokolova
Alexandra
A
Livshits
Vitaliy
V
Mashko
Sergey
S
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