JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 Elsen, S.
Right arrow Articles by Colbeau, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Elsen, S.
Right arrow Articles by Colbeau, A.

 Previous Article  |  Next Article 

Journal of Bacteriology, December 2003, p. 7111-7119, Vol. 185, No. 24
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.24.7111-7119.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Interaction between the H2 Sensor HupUV and the Histidine Kinase HupT Controls HupSL Hydrogenase Synthesis in Rhodobacter capsulatus

Sylvie Elsen, Ophélie Duché, and Annette Colbeau*

Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (UMR 5092 CNRS-CEA-UJF), Département Réponse et Dynamique Cellulaires, 38054 Grenoble Cedex 9, France

Received 17 July 2003/ Accepted 19 September 2003

The photosynthetic bacterium Rhodobacter capsulatus contains two [NiFe]hydrogenases: an energy-generating hydrogenase, HupSL, and a regulatory hydrogenase, HupUV. The synthesis of HupSL is specifically activated by H2 through a signal transduction cascade comprising three proteins: the H2-sensing HupUV protein, the histidine kinase HupT, and the transcriptional regulator HupR. Whereas a phosphotransfer between HupT and HupR was previously demonstrated, interaction between HupUV and HupT was only hypothesized based on in vivo analyses of mutant phenotypes. To visualize the in vitro interaction between HupUV and HupT proteins, a six-His (His6)-HupU fusion protein and the HupV protein were coproduced by using a homologous expression system. The two proteins copurified as a His6-HupUHupV complex present in dimeric and tetrameric forms, both of which had H2 uptake activity. We demonstrated that HupT and HupUV interact and form stable complexes that could be separated on a native gel. Interaction was also monitored with surface plasmon resonance technology and was shown to be insensitive to salt concentration and pH changes, suggesting that the interactions involve hydrophobic residues. As expected, H2 affects the interaction between HupUV and HupT, leading to a weakening of the interaction, which is independent of the phosphate status of HupT. Several forms of HupT were tested for their ability to interact with HupUV and to complement hupT mutants. Strong interaction with HupUV was obtained with the isolated PAS domain of HupT and with inactive HupT mutated in the phosphorylable histidine residue, but only the wild-type HupT protein was able to restore normal H2 regulation.

* Corresponding author. Mailing address: Laboratoire de Biochimie et Biophysique des Systèmes Intégrés, DRDC, CEA/Grenoble, 17 Rue des Martyrs, 38054 Grenoble Cedex 9, France. Phone: 33 (0)4 38 78 30 74. Fax: 33 (0)4 38 78 51 85. E-mail: acolbeau{at}cea.fr.

Journal of Bacteriology, December 2003, p. 7111-7119, Vol. 185, No. 24
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.24.7111-7119.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2003 by the American Society for Microbiology. All rights reserved.