CONSERVATION OF ORGANIZATION IN THE SPECIFICITY POLYPEPTIDES OF 2 FAMILIES OF TYPE-I RESTRICTION ENZYMES
CONSERVATION OF ORGANIZATION IN THE SPECIFICITY POLYPEPTIDES OF 2 FAMILIES OF TYPE-I RESTRICTION ENZYMES
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DOI：
10.1016/0022-2836(89)90001-6
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发表时间：
1989-10-05
影响因子：
5.6
通讯作者：
MURRAY, NE
中科院分区：
文献类型：
--
作者：
KANNAN, P;COWAN, GM;MURRAY, NE
我们已经鉴定了弗氏柠檬酸杆菌限制性内切酶 CfrA 的识别序列，CfrA 是 I 型 R-M 酶 A 家族的成员。这种二分靶序列的两个组成部分都与其他 I 型酶的组成部分不同。我们确定了其特异性基因 (hsdS) 的核苷酸序列，并将其与其相关的 EcoA 进行比较，确定了两个广泛的可变区，该组织类似于 I 型 R-M 酶 K 家族中发现的组织。与K的特异性多肽不同，A家族的特异性多肽具有N末端保守区，并且这包括在中央保守区内重复的序列。在氨基酸水平上鉴定的第二重复序列与所有I S型多肽共同的唯一序列相似性一致。 EcoA、CfrA、EcoK、B 和 D 的 hsdS 基因紧邻下游的序列几乎相同，与等位基因染色体位置一致。
We have identified the recognition sequence for the Citrobacter freundii restriction endonuclease CfrA, a member of the A-family of type I R-M enzymes. This bipartite target sequence differs in both its components from those of other type I enzymes. We determined the nucleotide sequence of its specificity gene (hsdS) and a comparison of this with its relative EcoA identifies two extensive variable regions, an organization analogous to that found in the K-family of type I R-M enzymes. The specificity polypeptides of the A-family, unlike those of K, have an N-terminal conserved region, and this includes a sequence repeated within the central conserved region. A second repeat sequence, identified at the amino acid level, coincides with the only sequence similarity common to all types I S polypeptides. Sequences immediately downstream from the hsdS genes of EcoA, CfrA, EcoK, B and D are almost identical, consistent with an allelic chromosomal location.