Interaction of transcriptional repressor ArgR with transcriptional regulator FarR at the argB promoter region in Corynebacterium glutamicum.
In Corynebacterium glutamicum, the ArgR protein, a transcriptional repressor, affects the expression level of the argB gene through binding to its promoter region. The argB promoter region (positions -77 to -25) has been found by in vitro electrophoretic mobility shift assay (EMSA) results and in silico analysis to be important for the DNA binding of ArgR. Proline supplementation prevented the DNA binding of ArgR to the argB promoter region and triggered an increase of the argB mRNA level. Additional mutational analyses of the argB promoter region found nucleotides critical for ArgR binding (G located at position -58, C at position -55, and A at position -41 of the argB promoter) in that region. Another transcriptional repressor, FarR, was also demonstrated to bind to the argB promoter region. This binding was delimited to positions -57 to -77 on the argB promoter. FarR has only one putative binding domain located at positions -57 to -77, but this region exactly overlapped with the binding region located from positions -55 to -77 for the binding of ArgR within the argB promoter; thus, if ArgR bound with the argB promoter first, the binding of FarR was not observed in this region. However, if FarR bound to the binding domain located at positions -57 to -77 first, ArgR could bind other binding sites located at positions -49 to -25 within the argB promoter. Finally, this study suggests that ArgR can affect FarR binding to the argB promoter region, as protein binding is dominated by the protein most able to do so.
Department of Bioprocess Engineering, Chonbuk National University, 664-14 Deokjin-dong, 1Ga Deokjin-Gu, Jeonju 561-756, South Korea.
Soo Youn
SY
Lee
Jae-Min
JM
Park
Jin Hyung
JH
Lee
Suk-Tai
ST
Chang
Jin-Soo
JS
Park
Yang-Hoon
YH
Kim
Jiho
J
Min
D001120:Arginine / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D011392:Proline / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C087018:ArgR protein, Bacteria; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D001120:Arginine; D011392:Proline