Lauster R, Kriebardis A, Guschlbauer W
FEBS Lett. 1987 Aug 10;220(1):167-76. doi: 10.1016/0014-5793(87)80897-9.
The amino acid sequence of EcoRV DNA methyltransferase which methylates the amino group of the 5'-adenine residue of the target sequence GATATC has been found to be closely related to that of three other adenine methyltransferases, DpnII, dam and damT4, the target sequence of which is GATC. Despite large differences on the DNA level, the four sequences show four blocks of homologies. One of these blocks has the sequence DVYXDPPY and is found with little modification in numerous other DNA methyltransferases. It is speculated that it could be the binding site of the methyl donor, S-adenosylmethionine. On the other hand, the identification of a DNA-binding region is more tenuous. As expected, no analogies with (dimeric) repressors and cro proteins which have the characteristic helix-turn-helix motif have been observed.
已发现对靶序列GATATC的5'-腺嘌呤残基的氨基进行甲基化的EcoRV DNA甲基转移酶的氨基酸序列与其他三种腺嘌呤甲基转移酶DpnII、dam和damT4的氨基酸序列密切相关,后三者的靶序列为GATC。尽管在DNA水平上存在很大差异,但这四个序列显示出四个同源区域。其中一个区域的序列为DVYXDPPY,在许多其他DNA甲基转移酶中也有少量修饰。据推测,它可能是甲基供体S-腺苷甲硫氨酸的结合位点。另一方面,DNA结合区域的鉴定则更为模糊。正如预期的那样,未观察到与具有特征性螺旋-转角-螺旋基序的(二聚体)阻遏蛋白和cro蛋白有类似之处。