【单选题】Which of the following enzymes cannot catalyze the formation of a phosphodiester bond?
E.
none of the choices are correct.
【单选题】The final phosphodiester bond between the fragments is made by .
【单选题】___________ restriction endonucleases, first isolated by Hamilton Smith in 1970, are r, require no ATP, and catalyze the hydrolytic cleavage of particular phosphodiester bonds in the DNA within ...
【单选题】Which of the following would pr the formation of a phosphodiester bond in DNA?
A.
removal of a nitrogen from one of the bases
B.
removal of oxygen from carbon 2 of the sugar
C.
removal of an oxygen from carbon 3 of the sugar or removal of the phosphate from the gamma position of the nucleoside triphosphate
D.
removal of the phosphate from the alpha position of the nucleoside triphosphate
E.
removal of the phosphate at the beta position of the nucleoside triphosphate
【单选题】Depurination does not break the DNA phosphodiester backbone but instead removes a purine base from a nucleotide, giving rise to lesions that resemble missing _____.
【单选题】随着变换反应的进行,变换率增大,最适宜温度()。
【单选题】DNA ligase catalyzes the formation of a phosphodiester bond between a 3′ hydroxyl at the end of one DNA strand and a 5′ phosphate at the end of another strand. The phosphate must be activated by adeny...
【单选题】Once the two fragments are joined, the final sealing phosphodiester bond is formed by