This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
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 Saikolappan, S.
Right arrow Articles by Dhandayuthapani, S.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Saikolappan, S.
Right arrow Articles by Dhandayuthapani, S.

 Previous Article  |  Next Article 

Journal of Bacteriology, November 2009, p. 6675-6682, Vol. 191, No. 21
0021-9193/09/$08.00+0     doi:10.1128/JB.01066-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

The Mycoplasma genitalium MG_454 Gene Product Resists Killing by Organic Hydroperoxides{triangledown} ,{dagger}

Sankaralingam Saikolappan,1,2 Smitha J. Sasindran,1,2 Hongwei D. Yu,3 Joel B. Baseman,2 and Subramanian Dhandayuthapani1,2*

Regional Academic Health Center, The University of Texas Health Science Center at San Antonio, Edinburg, Texas 78541,1 Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229,2 Department of Genetics, Biochemistry and Microbiology, Marshall University, Huntington, West Virginia 257553

Received 30 July 2009/ Accepted 21 August 2009

Mycoplasma genitalium is the smallest self-replicating organism and a successful human pathogen associated with a range of genitourinary maladies. As a consequence of its restricted genome size, genes that are highly conserved in other bacteria are absent in M. genitalium. Significantly, genes that encode antioxidants like superoxide dismutase and catalase-peroxidase are lacking. Nevertheless, comparative genomics has revealed that MG_454 of M. genitalium encodes a protein with putative function as an organic hydroperoxide reductase (Ohr). In this study, we found that an M. genitalium transposon mutant that lacks expression of MG_454 was sensitive to killing by t-butyl hydroperoxide and cumene hydroperoxide. To understand whether this sensitivity to hydroperoxides was linked to MG_454, we cloned this gene behind an arabinose-inducible PBAD promoter in plasmid pHERD20T and transformed this construct (pHERDMG454) into a Pseudomonas aeruginosa strain having deletion in its ohr gene (ohr mutant) and showing sensitivity to organic hydroperoxides. The P. aeruginosa ohr mutant harboring pHERDMG454, when induced with arabinose, was able to reverse its sensitivity to organic hydroperoxides, thus supporting the notion that the product of MG_454 resists organic hydroperoxides in M. genitalium. Surprisingly, real-time reverse transcription-PCR showed that expression of MG_454 in M. genitalium was not elevated in response to oxidative stress but was elevated in response to physical stresses, like salt (NaCl) and heat. Although failure of MG_454 to respond to oxidative stress in M. genitalium implies the absence of a known oxidative stress response regulator in the genome of M. genitalium, elevated expression of MG_454 due to physical stress suggests its control by an unidentified regulator.

* Corresponding author. Mailing address: Regional Academic Health Center, The University of Texas Health Science Center at San Antonio, 1214 West Schunior St., Edinburg, TX 78541. Phone: (956) 393-6431. Fax: (956) 393-6402. E-mail: dhandayutha{at}uthscsa.edu

{triangledown} Published ahead of print on 28 August 2009.

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

Journal of Bacteriology, November 2009, p. 6675-6682, Vol. 191, No. 21
0021-9193/09/$08.00+0     doi:10.1128/JB.01066-08
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»