Both purified human 1,N6-ethenoadenine-binding protein and purified human 3-methyladenine-DNA glycosylase act on 1,N6-ethenoadenine and 3-methyladenine.
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.
Singer
B
B
Donner Laboratory, Life Sciences Division, Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
Antoccia
A
A
Basu
A K
AK
Dosanjh
M K
MK
Fraenkel-Conrat
H
H
Gallagher
P E
PE
Kuśmierek
J T
JT
Qiu
Z H
ZH
Rydberg
B
B
D000225:Adenine / Q000031:analogs & derivatives* / Q000378:metabolism; D045647:DNA Glycosylases; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D009699:N-Glycosyl Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology; D013379:Substrate Specificity
D004268:DNA-Binding Proteins; C004981:1,N(6)-ethenoadenine; C025946:3-methyladenine; C021565:3-methyladenine-DNA glycosylase; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; D000225:Adenine