A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identi-fication and molecular characterization,the strains belonged to species of Yarrowia lipolytica,D...A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identi-fication and molecular characterization,the strains belonged to species of Yarrowia lipolytica,Debaryomyces hansenii,Rhodotorula slooffiae,Rhodotorula mucilaginosa,Sporidiobolus salmonicolor,Aureobasidium pullulans,Mrakia frigida and Guehomyces pullu-lans,respectively.The Antarctica yeasts have wide potential applications in biotechnology,for some of them can produce b-galactosidase and killer toxins.展开更多
Plant RNA N-glycosidase specifically hydrolyzes the N-C glycosidic bond of a conserved adenosine in the sarcin/ricin domain of the largest RNA in ribosome, releasing an adenine base and thus inhibiting protein synthes...Plant RNA N-glycosidase specifically hydrolyzes the N-C glycosidic bond of a conserved adenosine in the sarcin/ricin domain of the largest RNA in ribosome, releasing an adenine base and thus inhibiting protein synthesis. This substrate specificity was challenged later by discovery that various RNA derivatives and DNAs, especially the double-stranded supercoiled DNA could be used as substrate by RNA N-glycosidase. Thus, it was argued whether the DNA-cleaving activity was an intrinsic feature of RNA N-glycosidase or it was contaminated by DNase. In this article, several lines of evidence are presented to show that RNA N-glycosidase can really release the adenine base from the double-stranded supercoi/ed DNA. It was proposed that the cleavage mechanism of supercoiled DNA was the phosphodiester bonds in enzymatically deadenylated regions of the supercoiled DNA would become fragile and liable to produce nicked or linear form owing to the existence of tension in the supercoiled DNA molecule, not direct result of enzymatic action on the phosphodiester bond.展开更多
基金supported by the Hi-Tech Researchand Development Program of China(863),the grant No. is 2006AA09Z403
文摘A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identi-fication and molecular characterization,the strains belonged to species of Yarrowia lipolytica,Debaryomyces hansenii,Rhodotorula slooffiae,Rhodotorula mucilaginosa,Sporidiobolus salmonicolor,Aureobasidium pullulans,Mrakia frigida and Guehomyces pullu-lans,respectively.The Antarctica yeasts have wide potential applications in biotechnology,for some of them can produce b-galactosidase and killer toxins.
文摘Plant RNA N-glycosidase specifically hydrolyzes the N-C glycosidic bond of a conserved adenosine in the sarcin/ricin domain of the largest RNA in ribosome, releasing an adenine base and thus inhibiting protein synthesis. This substrate specificity was challenged later by discovery that various RNA derivatives and DNAs, especially the double-stranded supercoiled DNA could be used as substrate by RNA N-glycosidase. Thus, it was argued whether the DNA-cleaving activity was an intrinsic feature of RNA N-glycosidase or it was contaminated by DNase. In this article, several lines of evidence are presented to show that RNA N-glycosidase can really release the adenine base from the double-stranded supercoi/ed DNA. It was proposed that the cleavage mechanism of supercoiled DNA was the phosphodiester bonds in enzymatically deadenylated regions of the supercoiled DNA would become fragile and liable to produce nicked or linear form owing to the existence of tension in the supercoiled DNA molecule, not direct result of enzymatic action on the phosphodiester bond.
