A novel analytical principle using AP site-mediated T7 RNA polymerase transcription regulation for sensing uracil-DNA glycosylase activity

The Analyst ◽  
2020 ◽  
Vol 145 (12) ◽  
pp. 4321-4327
Author(s):  
Weichen Gao ◽  
Jin Xu ◽  
Guowei Lian ◽  
Xiaojun Wang ◽  
Xiaoqun Gong ◽  
...  

udg activity could regulate T7 RNA polymerase transcription ability by the heteroduplex substrates with chemical modifications.

2002 ◽  
Vol 365 (2) ◽  
pp. 547-553 ◽  
Author(s):  
Andrea SHATILLA ◽  
Dindial RAMOTAR

DNA bases continuously undergo modifications in response to endogenous reactions such as oxidation, alkylation or deamination. The modified bases are primarily removed by DNA glycosylases, which cleave the N-glycosylic bond linking the base to the sugar, to generate an apurinic/apyrimidinic (AP) site, and this latter lesion is highly mutagenic. Previously, no study has demonstrated the processing of these lesions in the nematode Caenorhabditis elegans. Herein, we report the existence of uracil-DNA glycosylase and AP endonuclease activities in extracts derived from embryos of C. elegans. These enzyme activities were monitored using a defined 5′-end 32P-labelled 42-bp synthetic oligonucleotide substrate bearing a single uracil residue opposite guanine at position 21. The embryonic extract rapidly cleaved the substrate in a time-dependent manner to produce a 20-mer product. The extract did not excise adenine or thymine opposite guanine, although uracil opposite either adenine or thymine was processed. Addition of the highly specific inhibitor of uracil-DNA glycosylase produced by Bacillus subtilis to the extract prevented the formation of the 20-mer product, indicating that removal of uracil is catalysed by uracil-DNA glycosylase. The data suggest that the 20-mer product was generated by a sequential reaction, i.e., removal of the uracil base followed by 5′-cleavage of the AP site. Further analysis revealed that product formation was dependent upon the presence of Mg2+, suggesting that cleavage of the AP site, following uracil excision, is carried out by a Mg2+-dependent AP endonuclease. It would appear that these activities correspond to the first two steps of a putative base-excision-repair pathway in C. elegans.


1987 ◽  
Vol 262 (9) ◽  
pp. 3940-3943
Author(s):  
M. Yamagishi ◽  
J.R. Cole ◽  
M. Nomura ◽  
F.W. Studier ◽  
J.J. Dunn

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