ABSTRACT
The genome of the facultative anaerobic thermoacidophilic archaeon Thermoplasma volcanium contains the open-reading frames (ORFs) tvsod and tvogg, which are predicted to encode a putative superoxide dismutase and an 8-oxoguanine DNA glycosylase, respectively. Tvsod is immediately upstream of tvogg, and these two ORFs are aligned in a head-to-tail manner in a single operon. A previous study showed that T. volcanium contains an ORF (TVN0292) encoding the ferric uptake regulator (Fur) and that the T. volcanium Fur protein (TvFur) binds to its own promoter in a metal-dependent manner in vitro. Here, we demonstrated that TvFur also binds to the tvsod-tvogg promoter and determined the TvFur-binding sequences in the tvsod-tvogg promoter by DNaseI footprinting analysis. These results suggest that Fur is required for resistance against reactive oxygen species in this facultative anaerobic archaeon.
Subject(s)
Bacterial Proteins/genetics , Genes, Bacterial , Operon , Oxidative Stress/genetics , Promoter Regions, Genetic , Repressor Proteins/genetics , Thermoplasma/genetics , Bacterial Proteins/metabolism , Base Sequence , Binding Sites , Molecular Sequence Data , Open Reading Frames , Repressor Proteins/metabolism , Thermoplasma/metabolismABSTRACT
In magnetic resonance imaging (MRI), the ideal phantom should have similar T1 and T2 values to those of organs of interest for measuring the change in signal intensity, contrast ratio and contrast noise ratio. There have been several reports to develop such a phantom using materials with limited availability or complex methods. In this study, we have developed a simple phantom using indigestible dextrin and soluble calcium at 1.5-tesla MRI. The T1 and T2 values have been reduced by dissolving indigestible dextrin and soluble calcium in distilled water. The similar T1 and T2 values to those of organs (i.e., kidney cortex, kidney medulla, liver, spleen, pancreas, bone marrow, uterus myometrium, uterus endometrium, uterus cervix, prostate, brain white matter, and brain gray matter) have been obtained by varying the concentration of indigestible dextrin and soluble calcium. This phantom is easy to develop and has a potential to increase the accuracy of MRI phantom experiments.
