Trans-aconitate methyltransferase regulator (TamR) is a member of the ligand-responsive multiple antibiotic resistance regulator (MarR) family of transcription factors. In Streptomyces coelicolor, TamR regulates transcription of tamR (encoding TamR), tam (encoding trans-aconitate methyltransferase) and sacA (encoding aconitase); up-regulation of these genes promotes metabolic flux through the citric acid cycle. DNA binding by TamR is attenuated and transcriptional derepression is achieved on binding of ligands such as citrate and trans-aconitate to TamR. In the present study, we show that three additional genes are regulated by S. coelicolor TamR. Genes encoding malate synthase (aceB1; SCO6243), malate dehydrogenase (mdh; SCO4827) and isocitrate dehydrogenase (idh; SCO7000) are up-regulated in vivo when citrate and trans-aconitate accumulate, and TamR binds the corresponding gene promoters in vitro, a DNA binding that is attenuated by cognate ligands. Mutations to the TamR binding site attenuate DNA binding in vitro and result in constitutive promoter activity in vivo. The predicted TamR binding sites are highly conserved in the promoters of these genes in Streptomyces species that encode divergent tam–tamR gene pairs, suggesting evolutionary conservation. Like aconitase and trans-aconitate methyltransferase, malate dehydrogenase, isocitrate dehydrogenase and malate synthase are closely related to the citric acid cycle, either catalysing individual reaction steps or, in the case of malate synthase, participating in the glyoxylate cycle to produce malate that enters the citric acid cycle to replenish the intermediate pool. Taken together, our data suggest that TamR plays an important and conserved role in promoting metabolic flux through the citric acid cycle.
Skip Nav Destination
Article navigation
March 2015
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkEditorial Board
Research Article|
February 20 2015
The regulatory role of Streptomyces coelicolor TamR in central metabolism
Hao Huang;
Hao Huang
1
*Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, U.S.A.
Search for other works by this author on:
Smitha Sivapragasam;
Smitha Sivapragasam
*Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, U.S.A.
Search for other works by this author on:
Anne Grove
Anne Grove
2
*Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, U.S.A.
2To whom correspondence should be addressed (email [email protected]).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
June 23 2013
Revision Received:
December 08 2014
Accepted:
December 11 2014
Accepted Manuscript online:
December 11 2014
Online ISSN: 1470-8728
Print ISSN: 0264-6021
© The Authors Journal compilation © 2015 Biochemical Society
2015
Biochem J (2015) 466 (2): 347–358.
Article history
Received:
June 23 2013
Revision Received:
December 08 2014
Accepted:
December 11 2014
Accepted Manuscript online:
December 11 2014
Citation
Hao Huang, Smitha Sivapragasam, Anne Grove; The regulatory role of Streptomyces coelicolor TamR in central metabolism. Biochem J 1 March 2015; 466 (2): 347–358. doi: https://doi.org/10.1042/BJ20130838
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.