| Title | Analysis of cepA Encoding an Efflux Pump-like Protein in Corynebacterium glutamicum |
|---|---|
| Author | Soo-Yeon Sim1, Eun-Ji Hong1, Younhee Kim2, and Heung-Shick Lee1* |
| Address | 1Department of Biotechnology and Bioinformatics, Korea University, Sejong 339-700, Republic of Korea, 2Department of Oriental Medicine, Semyung University, Chungbuk 390-230, Republic of Korea |
| Bibliography | Journal of Microbiology, 52(4),278–283, 2014, |
| DOI | 10.1007/s12275-014-3461-1 |
| Key Words | Corynebacterium glutamicum, cepA, efflux, purine |
| Abstract | A gene encoding a homolog of purine efflux proteins of Escherichia coli and Bacillus subtilis was identified in the genome of Corynebacterium glutamicum and designated as cepA. The gene encoded a putative protein product, containing 12 transmembrane helixes, which is a typical feature of integral membrane transport proteins. To elucidate the function of the gene, we constructed a cepA deletion mutant (ΔcepA) and a cepA-overexpressing strain and analyzed their physiological characteristics. The cepA gene could be deleted with no critical effect on cell growth. However, the cell yield of a ΔcepA strain was decreased by 10% as compared to that of a strain carrying a cepA-overexpression plasmid (P180-cepA). Further analysis identified increased resistance of the P180-cepA strain to the purine analogues 6-mercaptopurine and 6-mercaptoguanine, but not to 2-aminopurine and purine nucleoside analogues. Moreover, this strain showed increased resistance to the antibiotics nalidixic acid and ampicillin. Collectively, these data suggest that cepA is a novel multidrug resistance gene and probably functions in the efflux of toxic substances from the inside of cells to the environment, thus allowing cells to reach a higher cell yield. |