Lack of correlation between binding of EcoRII methyltransferase to DNA duplexes containing mismatches and the promotion of C to T mutations.
Lack of correlation between binding of EcoRII methyltransferase to DNA duplexes containing mismatches and the promotion of C to T mutations.
复制标题
EcoRII 甲基转移酶与含有错配的 DNA 双链体的结合与 C 到 T 突变的促进之间缺乏相关性。
DOI：
10.1007/s004380050474
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Bhagwat,AS
中科院分区：
文献类型：
--
作者：
Sheluho,D;Yebra,MJ;Khariwala,SS;Bhagwat,AS
The cytosine methyltransferases (MTases) M.HhaIand M.HpaII bind substrates in which the target cytosine is replaced by uracil or thymine, i.e. DNA containing a U:G or a T:G mismatch. We have extended this observation to theEcoRII MTase (M.EcoRII) and determined the apparent Kdfor binding. Using a genetic assay we have also tested the possibility that MTase binding to U:G mismatches may interfere with repair of the mismatches and promote C:G to T:A mutations. We have compared two mutants of M.EcoRII that are defective for catalysis by the wild-type enzyme for their ability to bind DNA containing U:G or T:G mismatches and for their ability to promote C to T mutations. We find that although all three proteins are able to bind DNAs with mismatches, only the wild-type enzyme promotes C:G to T:A mutations in vivo. Therefore, the ability of M.EcoRII to bind U:G mismatched duplexes is not sufficient for their mutagenic action in cells.
