This Article Full Text Full Text (PDF) Supplemental material Other Versions of this Article: JB.00755-07v1 189/19/7112    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Leduc, D. Articles by Bouveret, E. Search for Related Content PubMed PubMed Citation Articles by Leduc, D. Articles by Bouveret, E.

 Previous Article  |  Next Article 

Journal of Bacteriology, October 2007, p. 7112-7126, Vol. 189, No. 19
0021-9193/07/$08.00+0     doi:10.1128/JB.00755-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

The Hotdog Thioesterase EntH (YbdB) Plays a Role In Vivo in Optimal Enterobactin Biosynthesis by Interacting with the ArCP Domain of EntB ^,

Damien Leduc, Aurélia Battesti, and Emmanuelle Bouveret^*

LISM, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille, France

Received 14 May 2007/ Accepted 25 July 2007

In response to iron limitation, the siderophore enterobactin is synthesized and secreted by Escherichia coli. Its biosynthesis is performed by a series of enzymes encoded by the Ent gene cluster. Among the genes of this cluster, ybdB has not been implicated in enterobactin production to date. We demonstrate here an in vivo role for the hotdog protein EntH (YbdB) in the optimal production of enterobactin. Indeed, we showed that EntH is a thioesterase specifically produced under iron limitation conditions. Furthermore, EntH interacts specifically with the aryl carrier protein (ArCP) domain of EntB, a crucial bifunctional enzyme of the enterobactin biosynthesis pathway and a potential target of EntH thioesterase activity. A strain devoid of EntH is impaired for growth under iron limitation associated with the presence of the salicylate inhibitor, correlating with the diminution of enterobactin production under these conditions. Normal growth and enterobactin production are restored upon expression of entH in trans. Inversely, unnecessary overproduction of EntH provokes a fall of the quantity of siderophore produced under iron starvation conditions. Our findings point to a proofreading role for EntH during biosynthesis of enterobactin in vivo. EntH thioesterase activity could be required for cleaving wrongly charged molecules on the carrier protein EntB. This is the first description of such a role in the optimization of a nonribosomal biosynthesis pathway for a protein of the hotdog superfamily.

Published ahead of print on 3 August 2007.

Supplemental material for this article may be found at http://jb.asm.org/.

Present address: Pasteur Institute, 25 rue du Docteur Roux, 75015 Paris, France.