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 Maresca, J. A.
Right arrow Articles by Bryant, D. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Maresca, J. A.
Right arrow Articles by Bryant, D. A.

 Previous Article  |  Next Article 

Journal of Bacteriology, May 2004, p. 2558-2566, Vol. 186, No. 9
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.9.2558-2566.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

The bchU Gene of Chlorobium tepidum Encodes the C-20 Methyltransferase in Bacteriochlorophyll c Biosynthesis

Julia A. Maresca,1 Aline Gomez Maqueo Chew,1 Marta Ros Ponsatí,1,{dagger} Niels-Ulrik Frigaard,1 John G. Ormerod,2 and Donald A. Bryant1*

Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802,1 Department of Biology, University of Oslo, Blindern, N-0316, Oslo, Norway2

Received 12 November 2003/ Accepted 23 January 2004

Bacteriochlorophylls (BChls) c and d, two of the major light-harvesting pigments in photosynthetic green sulfur bacteria, differ only by the presence of a methyl group at the C-20 methine bridge position in BChl c. A gene potentially encoding the C-20 methyltransferase, bchU, was identified by comparative analysis of the Chlorobium tepidum and Chloroflexus aurantiacus genome sequences. Homologs of this gene were amplified and sequenced from Chlorobium phaeobacteroides strain 1549, Chlorobium vibrioforme strain 8327d, and C. vibrioforme strain 8327c, which produce BChls e, d, and c, respectively. A single nucleotide insertion in the bchU gene of C. vibrioforme strain 8327d was found to cause a premature, in-frame stop codon and thus the formation of a truncated, nonfunctional gene product. The spontaneous mutant of this strain that produces BChl c (strain 8327c) has a second frameshift mutation that restores the correct reading frame in bchU. The bchU gene was inactivated in C. tepidum, a BChl c-producing species, and the resulting mutant produced only BChl d. Growth rate measurements showed that BChl c- and d-producing strains of the same organism (C. tepidum or C. vibrioforme) have similar growth rates at high and intermediate light intensities but that strains producing BChl c grow faster than those with BChl d at low light intensities. Thus, the bchU gene encodes the C-20 methyltransferase for BChl c biosynthesis in Chlorobium species, and methylation at the C-20 position to produce BChl c rather than BChl d confers a significant competitive advantage to green sulfur bacteria living at limiting red and near-infrared light intensities.

* Corresponding author. Mailing address: S-234 Frear Building, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802. Phone: (814) 865-1992. Fax: (814) 863-7024. E-mail: dab14{at}psu.edu.

{dagger} Present address: Institute of Aquatic Ecology, University of Girona, Campus Montilivi, Girona E-17071, Spain.

Journal of Bacteriology, May 2004, p. 2558-2566, Vol. 186, No. 9
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.9.2558-2566.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Maresca, J. A., Romberger, S. P., Bryant, D. A. (2008). Isorenieratene Biosynthesis in Green Sulfur Bacteria Requires the Cooperative Actions of Two Carotenoid Cyclases. J. Bacteriol. 190: 6384-6391 [Abstract] [Full Text]  
  • Ito, H., Yokono, M., Tanaka, R., Tanaka, A. (2008). Identification of a Novel Vinyl Reductase Gene Essential for the Biosynthesis of Monovinyl Chlorophyll in Synechocystis sp. PCC6803. J. Biol. Chem. 283: 9002-9011 [Abstract] [Full Text]  
  • Chew, A. G. M., Frigaard, N.-U., Bryant, D. A. (2007). Bacteriochlorophyllide c C-82 and C-121 Methyltransferases Are Essential for Adaptation to Low Light in Chlorobaculum tepidum. J. Bacteriol. 189: 6176-6184 [Abstract] [Full Text]  
  • Nomata, J., Mizoguchi, T., Tamiaki, H., Fujita, Y. (2006). A Second Nitrogenase-like Enzyme for Bacteriochlorophyll Biosynthesis: RECONSTITUTION OF CHLOROPHYLLIDE a REDUCTASE WITH PURIFIED X-PROTEIN (BchX) AND YZ-PROTEIN (BchY-BchZ) FROM RHODOBACTER CAPSULATUS. J. Biol. Chem. 281: 15021-15028 [Abstract] [Full Text]  
  • Ley, R. E., Harris, J. K., Wilcox, J., Spear, J. R., Miller, S. R., Bebout, B. M., Maresca, J. A., Bryant, D. A., Sogin, M. L., Pace, N. R. (2006). Unexpected diversity and complexity of the guerrero negro hypersaline microbial mat.. Appl. Environ. Microbiol. 72: 3685-3695 [Abstract] [Full Text]  
  • Tsukatani, Y., Miyamoto, R., Itoh, S., Oh-oka, H. (2004). Function of a PscD Subunit in a Homodimeric Reaction Center Complex of the Photosynthetic Green Sulfur Bacterium Chlorobium tepidum Studied by Insertional Gene Inactivation: REGULATION OF ENERGY TRANSFER AND FERREDOXIN-MEDIATED NADP+ REDUCTION ON THE CYTOPLASMIC SIDE. J. Biol. Chem. 279: 51122-51130 [Abstract] [Full Text]  
  • Blankenship, R. E. (2004). Identification of a Key Step in the Biosynthetic Pathway of Bacteriochlorophyll c and Its Implications for Other Known and Unknown Green Sulfur Bacteria. J. Bacteriol. 186: 5187-5188 [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»