Singer B, Antoccia A, Basu A K, Dosanjh M K, Fraenkel-Conrat H, Gallagher P E, Kuśmierek J T, Qiu Z H, Rydberg B
Donner Laboratory, Life Sciences Division, Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9386-90. doi: 10.1073/pnas.89.20.9386.
We previously described a protein, isolated from human tissues and cells, that bound to a defined double-stranded oligonucleotide containing a single site-specifically placed 1,N6-ethenoadenine. It was further demonstrated that this protein was a glycosylase and released 1,N6-ethenoadenine. We now find that this enzyme also releases 3-methyladenine from methylated DNA and that 3-methyladenine-DNA glycosylase behaves in the same manner, binding to the ethenoadenine-containing oligonucleotide and cleaving both ethenoadenine and 3-methyladenine from DNA containing these adducts. The rate and extent of glycosylase activities toward the two adducts are similar.
我们之前描述过一种从人体组织和细胞中分离出的蛋白质，它能与一种特定的双链寡核苷酸结合，该寡核苷酸含有一个位点特异性放置的1,N6-乙烯腺嘌呤。进一步证明这种蛋白质是一种糖基化酶，能释放1,N6-乙烯腺嘌呤。我们现在发现这种酶还能从甲基化DNA中释放3-甲基腺嘌呤，并且3-甲基腺嘌呤-DNA糖基化酶也有同样的行为，即与含乙烯腺嘌呤的寡核苷酸结合，并从含有这些加合物的DNA中切割乙烯腺嘌呤和3-甲基腺嘌呤。糖基化酶对这两种加合物的活性速率和程度相似。
