JB Try MCB Online
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
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 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 Mongkolsuk, S.
Right arrow Articles by Supsamran, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mongkolsuk, S.
Right arrow Articles by Supsamran, N.

J. Bacteriol., Jun 1996, 3578-3584, Vol 178, No. 12
Copyright © 1996, American Society for Microbiology

Heterologous growth phase- and temperature-dependent expression and H2O2 toxicity protection of a superoxide-inducible monofunctional catalase gene from Xanthomonas oryzae pv. oryzae

S Mongkolsuk, S Loprasert, P Vattanaviboon, C Chanvanichayachai, S Chamnongpol and N Supsamran
Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok, Thailand.

Catalase is an important protective enzyme against H2O2 toxicity. Here, we report the characterization of a Xanthomonas oryzae pv. oryzae catalase gene (katX). The gene was localized and its nucleotide sequence was determined. The gene codes for a 77-kDa polypeptide. The deduced katX amino acid sequence shares regions of high identity with other monofunctional catalases in a range of organisms from bacteria to eukaryotes. The transcriptional regulation of katX was atypical of bacterial monofunctional kat genes. Northern (RNA) analysis showed that katX transcription was highly induced by treatments with low concentrations of menadione, a superoxide generator, and methyl methanesulfonate, a mutagen. It was only weakly induced by H2O2. Unlike in other bacteria, a high level of catalase in Xanthomonas spp. provided protection from the growth-inhibitory and killing effects of H2O2 but not from those of organic peroxides and superoxide generators. Unexpectedly, heterologous expression of katX in Escherichia coli was both growth phase and temperature dependent. Catalase activity in E. coli kat mutants harboring katX on an expression vector was detectable only when the cells entered the stationary phase of growth and at 28 degrees C. The patterns of transcription regulation, heterologous expression, and physiological function of katX are different from previously studied bacterial kat genes.


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 © 1996 by the American Society for Microbiology. All rights reserved.