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
Right arrow Citation Map
Services
Right arrow E-mail this article to a friend
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 Aly, H. A. H.
Right arrow Articles by Pieper, D. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Aly, H. A. H.
Right arrow Articles by Pieper, D. H.
Agricola
Right arrow Articles by Aly, H. A. H.
Right arrow Articles by Pieper, D. H.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, June 2008, p. 3812-3822, Vol. 74, No. 12
0099-2240/08/$08.00+0     doi:10.1128/AEM.00226-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Two Angular Dioxygenases Contribute to the Metabolic Versatility of Dibenzofuran-Degrading Rhodococcus sp. Strain HA01{triangledown}

Hamdy A. H. Aly,1,# Nguyen B. Huu,1,§ Victor Wray,2 Howard Junca,1 and Dietmar H. Pieper1*

Department of Environmental Microbiology,1 Department of Structural Biology, HZI-Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany2

Received 25 January 2008/ Accepted 19 April 2008

Rhodococcus sp. strain HA01, isolated through its ability to utilize dibenzofuran (DBF) as the sole carbon and energy source, was also capable, albeit with low activity, of transforming dibenzo-p-dioxin (DD). This strain could also transform 3-chlorodibenzofuran (3CDBF), mainly by angular oxygenation at the ether bond-carrying carbon (the angular position) and an adjacent carbon atom, to 4-chlorosalicylate as the end product. Similarly, 2-chlorodibenzofuran (2CDBF) was transformed to 5-chlorosalicylate. However, lateral oxygenation at the 3,4-positions was also observed and yielded the novel product 2-chloro-3,4-dihydro-3,4-dihydroxydibenzofuran. Two gene clusters encoding enzymes for angular oxygenation (dfdA1A2A3A4 and dbfA1A2) were isolated, and expression of both was observed during growth on DBF. Heterologous expression revealed that both oxygenase systems catalyze angular oxygenation of DBF and DD but exhibited complementary substrate specificity with respect to CDBF transformation. While DfdA1A2A3A4 oxygenase, with high similarity to DfdA1A2A3A4 oxygenase from Terrabacter sp. strain YK3, transforms 3CDBF by angular dioxygenation at a rate of 29% ± 4% that of DBF, 2CDBF was not transformed. In contrast, DbfA1A2 oxygenase, with high similarity to the DbfA1A2 oxygenase from Terrabacter sp. strain DBF63, exhibited complementary activity with angular oxygenase activity against 2CDBF but negligible activity against 3CDBF. Thus, Rhodococcus sp. strain HA01 constitutes the first described example of a bacterial strain where coexpression of two angular dioxygenases was observed. Such complementary activity allows for the efficient transformation of chlorinated DBFs.

* Corresponding author. Mailing address: Department of Environmental Microbiology, HZI-Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany. Phone: (49) 531 6181 4200. Fax: (49) 531 6181 4499. E-mail: dpi{at}helmholtz-hzi.de

{triangledown} Published ahead of print on 25 April 2008.

# Present address: GEBRI Genetic Engineering and Biotechnology Research Institute, Minufiya University, Sadat City, Egypt.

§ Present address: Department of Environmental Biotechnology, Institute of Biotechnology, Vietnamese Academy of Science and Technology, 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.

Applied and Environmental Microbiology, June 2008, p. 3812-3822, Vol. 74, No. 12
0099-2240/08/$08.00+0     doi:10.1128/AEM.00226-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Iida, T., Waki, T., Nakamura, K., Mukouzaka, Y., Kudo, T. (2009). The GAF-Like-Domain-Containing Transcriptional Regulator DfdR Is a Sensor Protein for Dibenzofuran and Several Hydrophobic Aromatic Compounds. J. Bacteriol. 191: 123-134 [Abstract] [Full Text]  


Copyright © 2010 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»