The katA catalase gene is regulated by OxyR in both free-living and symbiotic Sinorhizobium meliloti.
نویسندگان
چکیده
The characterization of an oxyR insertion mutant provides evidences that katA, which encodes the unique H2O2-inducible HPII catalase, is regulated by OxyR not only in free-living Sinorhizobium meliloti but also in symbiotic S. meliloti. Moreover, oxyR is expressed independently of exogenous H2O2 and downregulates its own expression in S. meliloti.
منابع مشابه
Role of oxyR from Sinorhizobium meliloti in regulating the expression of catalases.
The process of symbiotic nitrogen fixation results in the generation of reactive oxygen species such as the superoxide anion (O2-) and hydrogen peroxide (H2O2). The response of rhizobia to these toxic oxygen species is an important factor in nodulation and nitrogen fixation. In Sinorhizobium meliloti, one oxyR homologue and three catalase genes, katA, katB, and katC were detected by sequence an...
متن کاملDifferential regulation of two divergent Sinorhizobium meliloti genes for HPII-like catalases during free-living growth and protective role of both catalases during symbiosis.
Two catalases, KatA and KatB, have been detected in Sinorhizobium meliloti growing on rich medium. Here we characterize a new catalase gene encoding a third catalase (KatC). KatC activity was detectable only at the end of the stationary phase in S. meliloti growing in minimum medium, whereas KatA activity was found during the exponential phase. Analysis with a katC-lacZ fusion demonstrated that...
متن کاملGlutathione plays a fundamental role in growth and symbiotic capacity of Sinorhizobium meliloti.
Rhizobia form a symbiotic relationship with plants of the legume family to produce nitrogen-fixing root nodules under nitrogen-limiting conditions. We have examined the importance of glutathione (GSH) during free-living growth and symbiosis of Sinorhizobium meliloti. An S. meliloti mutant strain (SmgshA) which is unable to synthesize GSH due to a gene disruption in gshA, encoding the enzyme for...
متن کاملDisruption of sitA compromises Sinorhizobium meliloti for manganese uptake required for protection against oxidative stress.
During the initial stages of symbiosis with the host plant Medicago sativa, Sinorhizobium meliloti must overcome an oxidative burst produced by the plant in order for proper symbiotic development to continue. While identifying mutants defective in symbiosis and oxidative stress defense, we isolated a mutant with a transposon insertion mutation of sitA, which encodes the periplasmic binding prot...
متن کاملSmc01944, a secreted peroxidase induced by oxidative stresses in Sinorhizobium meliloti 1021.
Sequencing of the Sinorhizobium meliloti strain 1021 genome led to the detection of 6204 open reading frames, 41 % of which have no hypothetical function. To help annotate this genome, a transcriptome analysis was carried out with a dedicated microarray consisting of 146 genes belonging to three different classes: (i) no hypothetical function; (ii) potentially involved in oxidative stress respo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of bacteriology
دوره 187 1 شماره
صفحات -
تاریخ انتشار 2005