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
Google Scholar
Right arrow Articles by Kwon, Y.-M.
Right arrow Articles by Weiss, B.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kwon, Y.-M.
Right arrow Articles by Weiss, B.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 2009, p. 5369-5376, Vol. 191, No. 17
0021-9193/09/$08.00+0     doi:10.1128/JB.00586-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Production of 3-Nitrosoindole Derivatives by Escherichia coli during Anaerobic Growth{triangledown}

Young-Man Kwon and Bernard Weiss*

Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322

Received 5 May 2009/ Accepted 17 June 2009

When Escherichia coli K-12 is grown anaerobically in medium containing tryptophan and sodium nitrate, it produces red compounds. The reaction requires functional genes for trytophanase (tnaA), a tryptophan permease (tnaB), and a nitrate reductase (narG), as well as a natural drop in the pH of the culture. Mass spectrometry revealed that the purified chromophores had mass/charge ratios that closely match those for indole red, indoxyl red, and an indole trimer. These compounds are known products of chemical reactions between indole and nitrous acid. They are derived from an initial reaction of 3-nitrosoindole with indole. Apparently, nitrite that is produced from the metabolic reduction of nitrate is converted in the acid medium to nitrous acid, which leads to the nitrosation of the indole that is generated by tryptophanase. An nfi (endonuclease V) mutant and a recA mutant were selectively killed during the period of chromophore production, and a uvrA strain displayed reduced growth. These effects depended on the addition of nitrate to the medium and on tryptophanase activity in the cells. Unexpectedly, the killing of a tnaA+ nfi mutant was not accompanied by marked increases in mutation frequencies for several traits tested. The vulnerability of three DNA repair mutants indicates that a nitrosoindole or a derivative of a nitrosoindole produces lethal DNA damage.

* Corresponding author. Mailing address: Department of Pathology and Laboratory Medicine, Emory University, Whitehead Bldg., Rm. 141, 615 Michael St., Atlanta, GA 30322. Phone: (404) 712-2812. Fax: (404) 727-8538. E-mail: bweiss2{at}emory.edu

{triangledown} Published ahead of print on 26 June 2009.

Journal of Bacteriology, September 2009, p. 5369-5376, Vol. 191, No. 17
0021-9193/09/$08.00+0     doi:10.1128/JB.00586-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





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