title: A Na+-coupled C4-dicarboxylate transporter (Asuc_0304) and aerobic growth of Actinobacillus succinogenes on C4-dicarboxylates.
abstract: Actinobacillus succinogenes, which is known to produce large amounts of succinate during fermentation of hexoses, was able to grow on C4-dicarboxylates such as fumarate under aerobic and anaerobic conditions. Anaerobic growth on fumarate was stimulated by glycerol and the major product was succinate, indicating the involvement of fumarate respiration similar to succinate production from glucose. The aerobic growth on C4-dicarboxylates and the transport proteins involved were studied. Fumarate was oxidized to acetate. The genome of A. succinogenes encodes six proteins with similarity to secondary C4-dicarboxylate transporters, including transporters of the Dcu (C4-dicarboxylate uptake), DcuC (C4-dicarboxylate uptake C), DASS (divalent anion : sodium symporter) and TDT (tellurite resistance dicarboxylate transporter) family. From the cloned genes, Asuc_0304 of the DASS family protein was able to restore aerobic growth on C4-dicarboxylates in a C4-dicarboxylate-transport-negative Escherichia coli strain. The strain regained succinate or fumarate uptake, which was dependent on the electrochemical proton potential and the presence of Na(+). The transport had an optimum pH ~7, indicating transport of the dianionic C4-dicarboxylates. Transport competition experiments suggested substrate specificity for fumarate and succinate. The transport characteristics for C4-dicarboxylate uptake by cells of aerobically grown A. succinogenes were similar to those of Asuc_0304 expressed in E. coli, suggesting that Asuc_0304 has an important role in aerobic fumarate uptake in A. succinogenes. Asuc_0304 has sequence similarity to bacterial Na(+)-dicarboxylate cotransporters and contains the carboxylate-binding signature. Asuc_0304 was named SdcA (sodium-coupled C4-dicarboxylate transporter from A. succinogenes).
authors.affiliation: Department of Life Sciences, Division of EcoCreative, Ewha Womans University, 120-750 Seoul, Korea.
authors.forename: Mi Na
authors.initials: MN
authors.lastname: Rhie
authors.affiliation: Department of Life Sciences, Division of EcoCreative, Ewha Womans University, 120-750 Seoul, Korea.
authors.forename: Hyo Eun
authors.initials: HE
authors.lastname: Yoon
authors.affiliation: Department of Life Sciences, Division of EcoCreative, Ewha Womans University, 120-750 Seoul, Korea.
authors.forename: Hye Yun
authors.initials: HY
authors.lastname: Oh
authors.affiliation: Institute for Microbiology and Wine Research, Johannes Gutenberg University Mainz, Becherweg 15, 55099 Mainz, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Zedler
authors.affiliation: Institute for Microbiology and Wine Research, Johannes Gutenberg University Mainz, Becherweg 15, 55099 Mainz, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Unden
authors.affiliation: Department of Life Sciences, Division of EcoCreative, Ewha Womans University, 120-750 Seoul, Korea.
authors.forename: Ok Bin
authors.initials: OB
authors.lastname: Kim
mesh_terms: D000188:Actinobacillus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D000332:Aerobiosis; D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002250:Carbon Radioisotopes / Q000032:analysis; D029382:Dicarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism*; D003998:Dicarboxylic Acids / Q000378:metabolism; D005650:Fumarates / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D012964:Sodium / Q000378:metabolism; D013386:Succinates / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002250:Carbon Radioisotopes; D029382:Dicarboxylic Acid Transporters; D003998:Dicarboxylic Acids; D005650:Fumarates; D013386:Succinates; D012964:Sodium; D005947:Glucose