title: Expression and characterization of ArgR, an arginine regulatory protein in Corynebacterium crenatum.
abstract: OBJECTIVE
  Corynebacterium crenatum MT, a mutant from C. crenatum AS 1.542 with a lethal argR gene, exhibits high arginine production. To confirm the effect of ArgR on arginine biosynthesis in C. crenatum, an intact argR gene from wild-type AS 1.542 was introduced into C. crenatum MT, resulting in C. crenatum MT. sp, and the changes of transcriptional levels of the arginine biosynthetic genes and arginine production were compared between the mutant strain and the recombinant strain.
  
  
  METHODS
  Quantitative real-time polymerase chain reaction was employed to analyze the changes of the related genes at the transcriptional level, electrophoretic mobility shift assays were used to determine ArgR binding with the argCJBDF, argGH, and carAB promoter regions, and arginine production was determined with an automated amino acid analyzer.
  
  
  RESULTS
  Arginine production assays showed a 69.9% reduction in arginine from 9.01 ± 0.22 mg/mL in C. crenatum MT to 2.71 ± 0.13 mg/mL (P<0.05) in C. crenatum MT. sp. The argC, argB, argD, argF, argJ, argG, and carA genes were down-regulated significantly in C. crenatum MT. sp compared with those in its parental C. crenatum MT strain. The electrophoretic mobility shift assays showed that the promoter regions were directly bound to the ArgR protein.
  
  
  CONCLUSIONS
  The arginine biosynthetic genes in C. crenatum are clearly controlled by the negative regulator ArgR, and intact ArgR in C. crenatum MT results in a significant descrease in arginine production.
authors: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University, Nanchang 330022, Jiangxi, China.
authors: Xue Lan
authors: XL
authors: Chen
authors: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University, Nanchang 330022, Jiangxi, China.
authors: Bin
authors: B
authors: Zhang
authors: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University, Nanchang 330022, Jiangxi, China.
authors: Li
authors: L
authors: Tang
authors: Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University, Nanchang 330022, Jiangxi, China.
authors: Hai Tao
authors: HT
authors: Jiao
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, Jiangxi, China.
authors: Heng Yi
authors: HY
authors: Xu
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, Jiangxi, China.
authors: Feng
authors: F
authors: Xu
authors: Ocean NanoTech, LLC, Springdale, AR72764, USA.
authors: Hong
authors: H
authors: Xu
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, Jiangxi, China.
authors: Hua
authors: H
authors: Wei
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, Jiangxi, China.
authors: Yong Hua
authors: YH
authors: Xiong
mesh_terms: D001120:Arginine / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003352:Corynebacterium / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C087018:ArgR protein, Bacteria; D001426:Bacterial Proteins; D012097:Repressor Proteins; D001120:Arginine
keywords: ArgR protein; Arginine biosynthetic genes; Corynebacterium crenatum; Electrophoretic mobility shift assay; Real-time PCR