Publication: The oxyR from Agrobacterium tumefaciens: Evaluation of its role in the regulation of catalase and peroxide responses
Issued Date
2003-04-25
Resource Type
ISSN
0006291X
Other identifier(s)
2-s2.0-0037466483
Rights
Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
Biochemical and Biophysical Research Communications. Vol.304, No.1 (2003), 41-47
Suggested Citation
Kaewkanya Nakjarung, Skorn Mongkolsuk, Paiboon Vattanaviboon The oxyR from Agrobacterium tumefaciens: Evaluation of its role in the regulation of catalase and peroxide responses. Biochemical and Biophysical Research Communications. Vol.304, No.1 (2003), 41-47. doi:10.1016/S0006-291X(03)00535-7 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/20740
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
The oxyR from Agrobacterium tumefaciens: Evaluation of its role in the regulation of catalase and peroxide responses
Other Contributor(s)
Abstract
The gene for Agrobacterium tumefaciens OxyR, a peroxide sensor and transcriptional regulator, was characterized. Phylogenetic analysis of bacterial OxyR showed that the protein could be divided into four clades. The A. tumefaciens OxyR grouped in clade III that consists primarily of OxyRs of Alphaproteobacteria displayed the highest homology to OxyR from Rhizobium leguminosarum. oxyR is located next to, and is divergently transcribed from, a bifunctional catalase-peroxidase gene (katA). An A. tumefaciens oxyR mutant was constructed and shown to be hyper-sensitive to H2O2, but not to the superoxide generator, menadione, or an organic hydroperoxide. Exposure of A. tumefaciens to H2O2resulted in induction of the catalase-peroxidase enzyme. This induction was abolished in the oxyR mutant. In vivo analysis of a katA::lacZ promoter fusion confirmed the results of enzyme assays and indicated that induction of the katA promoter by H2O2was dependent on functional OxyR. We also examined the regulation of oxyR in A. tumefaciens. Exposure to H2O2did not induce expression of the gene but simply changed OxyR from a reduced to an oxidized form. The in vivo oxyR promoter analysis showed that the promoter was auto-regulated and that transcription was not induced by H2O2. © 2003 Elsevier Science (USA). All rights reserved.