6533b855fe1ef96bd12b13d5

RESEARCH PRODUCT

The L-tartrate/succinate antiporter TtdT (YgjE) of L-tartrate fermentation in Escherichia coli.

Ok Bin KimGottfried Unden

subject

biologyAntiporterPhysiology and MetabolismSuccinic AcidHeterologousSubstrate (chemistry)Biological TransportTartratebiology.organism_classificationmedicine.disease_causeMicrobiologychemistry.chemical_compoundBiochemistrychemistryBacterial ProteinsDehydrataseFermentationOperonmedicineEscherichia coliFermentationMolecular BiologyEscherichia coliTartratesBacteria

description

ABSTRACT Escherichia coli ferments l -tartrate under anaerobic conditions in the presence of an additional electron donor to succinate. The carrier for l -tartrate uptake and succinate export and its relation to the general C 4 -dicarboxylate carriers DcuA, DcuB, and DcuC were studied. The secondary carrier TtdT, encoded by the ttdT (previously called ygjE ) gene, is required for the uptake of l -tartrate. The ttdT gene is located downstream of the ttdA and ttdB genes, encoding the l -tartrate dehydratase TtdAB. Analysis of mRNA by reverse transcription-PCR showed that ttdA , ttdB , and ttdT are cotranscribed. Deletion of ttdT abolished growth by l -tartrate and degradation of l -tartrate completely. Bacteria containing TtdT catalyze l -tartrate or succinate uptake and specific heterologous l -tartrate/succinate antiporting. d -Tartrate is not a substrate for TtdT. TtdT operates preferentially in the direction of tartrate uptake and succinate excretion. The Dcu carriers do not support anaerobic growth on l -tartrate or l -tartrate transport. TtdT is related in sequence and function to CitT, which catalyzes heterologous citrate/succinate antiporting in citrate fermentation.

10.1128/jb.01402-06https://pubmed.ncbi.nlm.nih.gov/17172328