CONSERVATION OF COMPLEX DNA RECOGNITION DOMAINS BETWEEN FAMILIES OF RESTRICTION ENZYMES
CONSERVATION OF COMPLEX DNA RECOGNITION DOMAINS BETWEEN FAMILIES OF RESTRICTION ENZYMES
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DOI：
10.1016/0092-8674(89)90988-4
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发表时间：
1989-01-13
期刊：
影响因子：
64.5
通讯作者：
MURRAY, NE
中科院分区：
文献类型：
--
作者：
COWAN, GM;GANN, AAF;MURRAY, NE
一种多肽，命名为S，赋予多亚基I型限制酶序列特异性。这类酶的两个家族，K和A，包括识别不同的、二分的靶序列的成员。K家族的S多肽虽然具有接近同一性的区域，但也含有两个广泛的可变序列区。我们现在表明，其中一个包含N末端150个氨基酸，指定识别二分靶序列的一个组分。我们已经确定了A家族成员EcoE识别的序列。该序列5 '' GAG（N7）ATGC具有与K家族的EcoA和StySB相同的三核苷酸GAG。我们确定了EcoA和EcoE的S基因的核苷酸序列，并将它们预测的氨基酸序列相互比较，并与K家族的五个成员进行比较。家族之间没有一般的序列相似性，但是StySB的S多肽的结构域（其指定GAG）与EcoA和EcoE的S多肽的氨基可变区显示出近50%的同一性。因此，识别和指导GAG甲基化的复杂结构域对于通常不同氨基酸序列的酶是共同的。
One polypeptide, designated S, confers sequence-specificity to the multisubunit type I restriction enzymes. Two families of such enzymes, K and A, include members that recognize diverse, bipartite, target sequences. The S polypeptides of the K family, while having areas of near identity, also contain two extensive regions of variable sequence. We now show that one of these, comprising the N-terminal 150 amino acids, specifies recognition of one component of the bipartite target sequence. We have determined the sequence recognized by EcoE, a member of the A family. This sequence, 5''GAG(N7)ATGC, has the trinucleotide GAG in common with EcoA and with StySB of the K family. We determined the nucleotide sequences of the S genes of EcoA and EcoE, and compared their predicted amino acid sequences with each other and with those of the five members of the K family. There is no general sequence similarity between families, but the domain of the S polypeptide of StySB, which specifies GAG, shows nearly 50 percent identity with the amino variable region of the S polypeptides of EcoA and EcoE. A complex domain that recognizes and directs methylation of GAG is therefore common to enzymes of generally dissimilar amino acid sequence.