title: SATP (YaaH), a succinate-acetate transporter protein in Escherichia coli.
abstract: In the present paper 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), with affinity constants at pH 6.0 of 1.24±0.13 mM for acetic acid and 1.18±0.10 mM for 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, described previously 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. Owing to its functional role in acetate and succinate uptake we propose its assignment as SatP: the Succinate-Acetate Transporter Protein.
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Sá-Pessoa
authors.forename: Sandra
authors.initials: S
authors.lastname: Paiva
authors.forename: David
authors.initials: D
authors.lastname: Ribas
authors.forename: Inês Jesus
authors.initials: IJ
authors.lastname: Silva
authors.forename: Sandra Cristina
authors.initials: SC
authors.lastname: Viegas
authors.forename: Cecília Maria
authors.initials: CM
authors.lastname: Arraiano
authors.forename: Margarida
authors.initials: M
authors.lastname: Casal
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001692:Biological Transport; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D055786:Gene Knockout Techniques; D007700:Kinetics; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D027501:Monocarboxylic Acid Transporters / Q000235:genetics* / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D027361:Organic Anion Transporters / Q000235:genetics* / Q000378:metabolism; D013379:Substrate Specificity; D019802:Succinic Acid / Q000378:metabolism*
chemical_list: C478943:ActP protein, E coli; D029968:Escherichia coli Proteins; D027501:Monocarboxylic Acid Transporters; D027361:Organic Anion Transporters; C584117:SatP protein, E coli; D019802:Succinic Acid; D019342:Acetic Acid