SatP (YaaH), a succinate-acetate transporter protein in Escherichia coli

In this work we describe a new carboxylic acid transporter in Escherichia coli encoded by the gene yaaH. In contrast to what had been described for other YaaH family members, the E. coli transporter is highly specific for acetic acid (a monocarboxylate) and for succinic acid (a dicarboxylate), presenting the following affinity constants at pH 6.0, 1.24 ± 0.13 mM acetic acid and 1.18 ± 0.10 mM succinic acid. In glucose grown-cells the ΔyaaH mutant is compromised for the uptake of both labelled acetic and succinic acids. YaaH, together with ActP, previously described as an acetate transporter, affect the use of acetic acid as sole carbon and energy source. Both genes have to be deleted simultaneously to abolish acetate transport. The uptake of acetate and succinate was restored when yaaH was expressed in trans in ΔyaaH ΔactP cells. We also demonstrate the critical role of YaaH amino acid residues Leu131 and Ala164 on the enhanced ability to transport lactate. Due to its functional role in acetate and succinate uptake we propose its assignment as SatP: the Succinate-Acetate Transporter Protein.
Source: BJ Cell - Category: Biochemistry Authors: Tags: BJ Cell Source Type: research