High‐affinityl ‐malate transporter DcuE ofActinobacillus succinogenescatalyses reversible exchange of C4‐dicarboxylates
| Autor: | Yeon Joo Lee, Mi Na Rhie, Young Bin Cho, Ok Bin Kim |
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| Rok vydání: | 2018 |
| Předmět: |
Antiporter
Malates Succinic Acid medicine.disease_cause Antiporters Catalysis Substrate Specificity 03 medical and health sciences Non-competitive inhibition Bacterial Proteins Fumarates Respiration Escherichia coli medicine Dicarboxylic Acids Anaerobiosis Ecology Evolution Behavior and Systematics 030304 developmental biology Dicarboxylic Acid Transporters 0303 health sciences biology 030306 microbiology Chemistry Genetic Complementation Test Substrate (chemistry) Biological Transport Transporter Actinobacillus biology.organism_classification Agricultural and Biological Sciences (miscellaneous) Kinetics Actinobacillus succinogenes Biochemistry Efflux |
| Zdroj: | Environmental Microbiology Reports. 11:129-139 |
| ISSN: | 1758-2229 |
| DOI: | 10.1111/1758-2229.12719 |
| Popis: | Actinobacillus succinogenes is a natural succinate producer, which is the result of fumarate respiration. Succinate production from anaerobic growth with C4 -dicarboxylates requires transporters catalysing uptake and efflux of C4 -dicarboxylates. Transporter Asuc_1999 (DcuE) found in A. succinogenes belongs to the Dcu family and was considered the main transporter for fumarate respiration. However, deletion of dcuE affected l-malate uptake of A. succinogenes rather than fumarate uptake. DcuE complemented anaerobic growth of Escherichia coli on l-malate or fumarate; thus, the transporter was characterized in E. coli heterologously. Time-dependent uptake and competitive inhibition assays demonstrated that l-malate is the most preferred substrate for uptake by DcuE. The Vmax of DcuE for l-malate was 20.04 μmol/gDW·min with Km of 57 μM. The Vmax for l-malate was comparable to that for fumarate, whereas the Km for l-malate was 8 times lower than that for fumarate. The catalytic efficiency of DcuE for l-malate was 7.3-fold higher than that for fumarate, showing high efficiency and high affinity for l-malate. Furthermore, DcuE catalysed the reversible exchange of three C4 -dicarboxylates - l-malate, fumarate and succinate - but the preferred substrate for uptake was l-malate. Under physiological conditions, the C4 -dicarboxylates were reduced to succinate. Therefore, DcuE is proposed as the l-malate/succinate antiporter in A. succinogenes. |
| Databáze: | OpenAIRE |
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