This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Subrahmanyam, S.
Right arrow Articles by Cronan, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Subrahmanyam, S.
Right arrow Articles by Cronan, J. E., Jr.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 1998, p. 4596-4602, Vol. 180, No. 17
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Overproduction of a Functional Fatty Acid Biosynthetic Enzyme Blocks Fatty Acid Synthesis in Escherichia coli

Satyanarayana Subrahmanyam1 and John E. Cronan Jr.1,2,*

Departments of Microbiology1 and Biochemistry,2 University of Illinois, Urbana, Illinois 61801

Received 2 March 1998/Accepted 22 June 1998

beta -Ketoacyl-acyl carrier protein (ACP) synthetase II (KAS II) is one of three Escherichia coli isozymes that catalyze the elongation of growing fatty acid chains by condensation of acyl-ACP with malonyl-ACP. Overexpression of this enzyme has been found to be extremely toxic to E. coli, much more so than overproduction of either of the other KAS isozymes, KAS I or KAS III. The immediate effect of KAS II overproduction is the cessation of phospholipid synthesis, and this inhibition is specifically due to the blockage of fatty acid synthesis. To determine the cause of this inhibition, we examined the intracellular pools of ACP, coenzyme A (CoA), and their acyl thioesters. Although no significant changes were detected in the acyl-ACP pools, the CoA pools were dramatically altered by KAS II overproduction. Malonyl-CoA increased to about 40% of the total cellular CoA pool upon KAS II overproduction from a steady-state level of around 0.5% in the absence of KAS II overproduction. This finding indicated that the conversion of malonyl-CoA to fatty acids had been blocked and could be explained if either the conversion of malonyl-CoA to malonyl-ACP and/or the elongation reactions of fatty acid synthesis had been blocked. Overproduction of malonyl-CoA:ACP transacylase, the enzyme catalyzing the conversion of malonyl-CoA to malonyl-ACP, partially relieved the toxicity of KAS II overproduction, consistent with a model in which high levels of KAS II blocks access of the other KAS isozymes to malonyl-CoA:ACP transacylase.

* Corresponding author. Mailing address: Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 South Goodwin Ave., Urbana, IL 61801. Phone: (217) 333-0425. Fax: (217) 244-6697. E-mail: j-cronan{at}uiuc.edu.

Journal of Bacteriology, September 1998, p. 4596-4602, Vol. 180, No. 17
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Kizer, L., Pitera, D. J., Pfleger, B. F., Keasling, J. D. (2008). Application of Functional Genomics to Pathway Optimization for Increased Isoprenoid Production. Appl. Environ. Microbiol. 74: 3229-3241 [Abstract] [Full Text]  
  • Iram, S. H., Cronan, J. E. (2006). The {beta}-Oxidation Systems of Escherichia coli and Salmonella enterica Are Not Functionally Equivalent. J. Bacteriol. 188: 599-608 [Abstract] [Full Text]  
  • Morgan-Kiss, R. M., Cronan, J. E. (2004). The Escherichia coli fadK (ydiD) Gene Encodes an Anerobically Regulated Short Chain Acyl-CoA Synthetase. J. Biol. Chem. 279: 37324-37333 [Abstract] [Full Text]  
  • Campbell, J. W., Cronan, J. E. Jr. (2001). Escherichia coli FadR Positively Regulates Transcription of the fabB Fatty Acid Biosynthetic Gene. J. Bacteriol. 183: 5982-5990 [Abstract] [Full Text]  
  • Allen, E. E., Bartlett, D. H. (2000). FabF Is Required for Piezoregulation of cis-Vaccenic Acid Levels and Piezophilic Growth of the Deep-Sea Bacterium Photobacterium profundum Strain SS9. J. Bacteriol. 182: 1264-1271 [Abstract] [Full Text]  
  • Davis, M. S., Solbiati, J., Cronan, J. E. Jr. (2000). Overproduction of Acetyl-CoA Carboxylase Activity Increases the Rate of Fatty Acid Biosynthesis in Escherichia coli. J. Biol. Chem. 275: 28593-28598 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»