Gautam Shweta D, Chen Jon K, Murray Vincent
School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
J Biol Inorg Chem. 2017 Aug;22(6):881-892. doi: 10.1007/s00775-017-1466-z. Epub 2017 May 16.
Bleomycin is an anti-tumour agent that is clinically used to treat several types of cancers. Bleomycin cleaves DNA at specific DNA sequences and recent genome-wide DNA sequencing specificity data indicated that the sequence 5'-RTGTAY (where T is the site of bleomycin cleavage, R is G/A and Y is T/C) is preferentially cleaved by bleomycin in human cells. Based on this DNA sequence, we constructed a plasmid clone to explore this bleomycin cleavage preference. By systematic variation of single nucleotides in the 5'-RTGTAY sequence, we were able to investigate the effect of nucleotide changes on bleomycin cleavage efficiency. We observed that the preferred consensus DNA sequence for bleomycin cleavage in the plasmid clone was 5'-YYGTAW (where W is A/T). The most highly cleaved sequence was 5'-TCGTAT and, in fact, the seven most highly cleaved sequences conformed to the consensus sequence 5'-YYGTAW. A comparison with genome-wide results was also performed and while the core sequence was similar in both environments, the surrounding nucleotides were different.
博来霉素是一种抗肿瘤药物，临床上用于治疗多种类型的癌症。博来霉素在特定的DNA序列处切割DNA，最近全基因组DNA测序特异性数据表明，序列5'-RTGTAY（其中T是博来霉素切割位点，R为G/A，Y为T/C）在人类细胞中被博来霉素优先切割。基于此DNA序列，我们构建了一个质粒克隆来探究这种博来霉素切割偏好。通过对5'-RTGTAY序列中的单核苷酸进行系统变异，我们能够研究核苷酸变化对博来霉素切割效率的影响。我们观察到，质粒克隆中博来霉素切割的首选共有DNA序列为5'-YYGTAW（其中W为A/T）。切割程度最高的序列是5'-TCGTAT，实际上，切割程度最高的七个序列符合共有序列5'-YYGTAW。我们还进行了与全基因组结果的比较，虽然两种环境中的核心序列相似，但周围的核苷酸不同。
