Identification of AcnR, a TetR-type repressor of the aconitase gene acn in Corynebacterium glutamicum.
J Biol Chem. 2005 Jan 07; 280(1):585-95.JB

Abstract

In Corynebacterium glutamicum, the activity of aconitase is 2.5-4-fold higher on propionate, citrate, or acetate than on glucose. Here we show that this variation is caused by transcriptional regulation. In search for putative regulators, a gene (acnR) encoding a TetR-type transcriptional regulator was found to be encoded immediately downstream of the aconitase gene (acn) in C. glutamicum. Deletion of the acnR gene led to a 5-fold increased acn-mRNA level and a 5-fold increased aconitase activity, suggesting that AcnR functions as repressor of acn expression. DNA microarray analyses indicated that acn is the primary target gene of AcnR in the C. glutamicum genome. Purified AcnR was shown to be a homodimer, which binds to the acn promoter in the region from -11 to -28 relative to the transcription start. It thus presumably acts by interfering with the binding of RNA polymerase. The acn-acnR organization is conserved in all corynebacteria and mycobacteria with known genome sequence and a putative AcnR consensus binding motif (CAGNACnnncGTACTG) was identified in the corresponding acn upstream regions. Mutations within this motif inhibited AcnR binding. Because the activities of citrate synthase and isocitrate dehydrogenase were previously reported not to be increased during growth on acetate, our data indicate that aconitase is a major control point of tricarboxylic acid cycle activity in C. glutamicum, and they identify AcnR as the first transcriptional regulator of a tricarboxylic acid cycle gene in the Corynebacterianeae.

Authors+Show Affiliations

Krug A

Institut für Biotechnologie 1, Forschungszentrum Jülich, D-52425 Jülich, Germany.

Wendisch VF

No affiliation info available

Bott M

No affiliation info available

MeSH

Aconitate HydrataseAmino Acid SequenceBacterial ProteinsCorynebacterium glutamicumGene Expression Regulation, BacterialGenes, BacterialGenes, RegulatorMolecular Sequence DataRepressor ProteinsSequence AlignmentSpecies SpecificityTranscriptional Activation

Pub Type(s)

Journal Article

Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15494411

Citation

Krug, Andreas, et al. "Identification of AcnR, a TetR-type Repressor of the Aconitase Gene Acn in Corynebacterium Glutamicum." The Journal of Biological Chemistry, vol. 280, no. 1, 2005, pp. 585-95.

Krug A, Wendisch VF, Bott M. Identification of AcnR, a TetR-type repressor of the aconitase gene acn in Corynebacterium glutamicum. J Biol Chem. 2005;280(1):585-95.

Krug, A., Wendisch, V. F., & Bott, M. (2005). Identification of AcnR, a TetR-type repressor of the aconitase gene acn in Corynebacterium glutamicum. The Journal of Biological Chemistry, 280(1), 585-95.

Krug A, Wendisch VF, Bott M. Identification of AcnR, a TetR-type Repressor of the Aconitase Gene Acn in Corynebacterium Glutamicum. J Biol Chem. 2005 Jan 7;280(1):585-95. PubMed PMID: 15494411.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Identification of AcnR, a TetR-type repressor of the aconitase gene acn in Corynebacterium glutamicum. AU - Krug,Andreas, AU - Wendisch,Volker F, AU - Bott,Michael, Y1 - 2004/10/19/ PY - 2004/10/21/pubmed PY - 2005/7/22/medline PY - 2004/10/21/entrez SP - 585 EP - 95 JF - The Journal of biological chemistry JO - J Biol Chem VL - 280 IS - 1 N2 - In Corynebacterium glutamicum, the activity of aconitase is 2.5-4-fold higher on propionate, citrate, or acetate than on glucose. Here we show that this variation is caused by transcriptional regulation. In search for putative regulators, a gene (acnR) encoding a TetR-type transcriptional regulator was found to be encoded immediately downstream of the aconitase gene (acn) in C. glutamicum. Deletion of the acnR gene led to a 5-fold increased acn-mRNA level and a 5-fold increased aconitase activity, suggesting that AcnR functions as repressor of acn expression. DNA microarray analyses indicated that acn is the primary target gene of AcnR in the C. glutamicum genome. Purified AcnR was shown to be a homodimer, which binds to the acn promoter in the region from -11 to -28 relative to the transcription start. It thus presumably acts by interfering with the binding of RNA polymerase. The acn-acnR organization is conserved in all corynebacteria and mycobacteria with known genome sequence and a putative AcnR consensus binding motif (CAGNACnnncGTACTG) was identified in the corresponding acn upstream regions. Mutations within this motif inhibited AcnR binding. Because the activities of citrate synthase and isocitrate dehydrogenase were previously reported not to be increased during growth on acetate, our data indicate that aconitase is a major control point of tricarboxylic acid cycle activity in C. glutamicum, and they identify AcnR as the first transcriptional regulator of a tricarboxylic acid cycle gene in the Corynebacterianeae. SN - 0021-9258 UR - https://www.unboundmedicine.com/medline/citation/15494411/Identification_of_AcnR_a_TetR_type_repressor_of_the_aconitase_gene_acn_in_Corynebacterium_glutamicum_ DB - PRIME DP - Unbound Medicine ER -

Tags

Identification of AcnR, a TetR-type repressor of the aconitase gene acn in Corynebacterium glutamicum.J Biol Chem. 2005 Jan 07; 280(1):585-95.JB