Proline reduces the binding of transcriptional regulator ArgR to upstream of argB in Corynebacterium glutamicum.
In this study, the ArgR-binding sites on the arg operon Corynbebacterium glutamicum were characterized by in vivo chromatin immunoprecipitation (ChIP). In addition, the ArgR-binding affinity in the presence of glutamate, proline, or arginine was examined to get further information on expression control. The ChIP assay showed that the ArgR protein binds specifically to the upstream regions of argC, argB, argF, and argG. Upon proline supplementation, ArgR-binding affinity was significantly reduced upstream of argB, resulting in increased ornithine production. In contrast, there was no change in the binding affinity of ArgR to the upstream regions of argC, argF, argG, or argB following the addition of glutamate and arginine. These results suggest that the upstream region of argB on the arg operon plays an important role in interacting with ArgR under proline-supplemented conditions and that proline causes an increase in the endogenous level of ornithine by reducing the binding affinity of ArgR to the upstream region of argB.
Lee
Soo Youn
SY
Department of Bioprocess Engineering, Chonbuk National University, 664-14 Duckjin-dong, Jeonju 561-756, South Korea.
Shin
Hwa Sung
HS
Park
Jin-Soo
JS
Kim
Yang-Hoon
YH
Min
Jiho
J
D001120:Arginine / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D047369:Chromatin Immunoprecipitation; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018698:Glutamic Acid / Q000378:metabolism; D009876:Operon; D009952:Ornithine / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
C087018:ArgR protein, Bacteria; D001426:Bacterial Proteins; D012097:Repressor Proteins; D018698:Glutamic Acid; D001120:Arginine; D011392:Proline; D009952:Ornithine