Low selenium (Se) belt in the Loess Plateau constitutes anessential part of low Se belt in China. Se backgound of loess is only46.5 ug/kg. Centre of low Se content in soil surface is situated in thecentral-north of th...Low selenium (Se) belt in the Loess Plateau constitutes anessential part of low Se belt in China. Se backgound of loess is only46.5 ug/kg. Centre of low Se content in soil surface is situated in thecentral-north of the Loess Plateau, While Se background of soilsurface in southwest is higher because of less precipitation, and thatin southeast is higher too owing to finer soil texture. Both of themare divided into low and normal Se eco-environment by precipitationof 450 mm, a transition from subhumid to semiarid climate.Contents of mobile elements in drinking water are negativelycorrelated wtth precipitatioll. The same happens in soils except Se.But Se content in soils with closed conditions is negntivelycorrelated with precipitation as well. These susaest thatprecipitation plays a key role in differentiating Se eco-environmentother than the centre of low Se content in soil surface.展开更多
Incorporation of Selenocysteine into protein requires an RNA structural motif, SECIS (Selenocysteine insertion sequence) element that, along with other factors, demarcates UGA-Sec from the UGA termination codon, for e...Incorporation of Selenocysteine into protein requires an RNA structural motif, SECIS (Selenocysteine insertion sequence) element that, along with other factors, demarcates UGA-Sec from the UGA termination codon, for expression of Selenoproteins (in case of eukaryotes). It has been predicted that during HIV infection, several functional viral selenoproteins are expressed and synthesis of these viral selenoproteins deplete the selenium level of the host. It might be that even the viral genome has the SECIS elements in their Selenoprotein mRNA, and during infection, the host cellular machinery is transformed in such a way that the human Sec tRNA binds to the viral Selenoprotein mRNA, instead of binding to its own Selenoprotein mRNA, thus leading to expression of viral selenoproteins. This hypothesis was tested in this study by identifying the SECIS elements in the HIV-1 genome and further predicting their secondary and tertiary structures. We then tried to dock these tertiary structures with human Sec tRNA. Here we report putatively the presence of 3215 SECIS elements in the HIV-1 genome and that the human Sec tRNAsec binds to the viral SECIS elements present in the viral selenoprotein mRNA. Based on an earlier finding, it was observed that atoms of A8 and U9, which present in human Sec tRNA, are the possible key sites for binding.展开更多
文摘Low selenium (Se) belt in the Loess Plateau constitutes anessential part of low Se belt in China. Se backgound of loess is only46.5 ug/kg. Centre of low Se content in soil surface is situated in thecentral-north of the Loess Plateau, While Se background of soilsurface in southwest is higher because of less precipitation, and thatin southeast is higher too owing to finer soil texture. Both of themare divided into low and normal Se eco-environment by precipitationof 450 mm, a transition from subhumid to semiarid climate.Contents of mobile elements in drinking water are negativelycorrelated wtth precipitatioll. The same happens in soils except Se.But Se content in soils with closed conditions is negntivelycorrelated with precipitation as well. These susaest thatprecipitation plays a key role in differentiating Se eco-environmentother than the centre of low Se content in soil surface.
文摘Incorporation of Selenocysteine into protein requires an RNA structural motif, SECIS (Selenocysteine insertion sequence) element that, along with other factors, demarcates UGA-Sec from the UGA termination codon, for expression of Selenoproteins (in case of eukaryotes). It has been predicted that during HIV infection, several functional viral selenoproteins are expressed and synthesis of these viral selenoproteins deplete the selenium level of the host. It might be that even the viral genome has the SECIS elements in their Selenoprotein mRNA, and during infection, the host cellular machinery is transformed in such a way that the human Sec tRNA binds to the viral Selenoprotein mRNA, instead of binding to its own Selenoprotein mRNA, thus leading to expression of viral selenoproteins. This hypothesis was tested in this study by identifying the SECIS elements in the HIV-1 genome and further predicting their secondary and tertiary structures. We then tried to dock these tertiary structures with human Sec tRNA. Here we report putatively the presence of 3215 SECIS elements in the HIV-1 genome and that the human Sec tRNAsec binds to the viral SECIS elements present in the viral selenoprotein mRNA. Based on an earlier finding, it was observed that atoms of A8 and U9, which present in human Sec tRNA, are the possible key sites for binding.
