来自支原体的CAATTG特异性限制修饰munI基因：R.MunI与R.EcoRI之间的序列相似性

CAATTG-specific restriction-modification munI genes from Mycoplasma: sequence similarities between R.MunI and R.EcoRI.

作者信息

Siksnys V, Zareckaja N, Vaisvila R, Timinskas A, Stakenas P, Butkus V, Janulaitis A

机构信息

Institute of Biotechnology FERMENTAS, Vilnius, Lithuania.

出版信息

Gene. 1994 May 3;142(1):1-8. doi: 10.1016/0378-1119(94)90347-6.

DOI:10.1016/0378-1119(94)90347-6

PMID:8181741

Abstract

The genes coding for the MunI restriction-modification (R-M) system, which recognize the sequence 5'-CAATTG, have been cloned and expressed in Escherichia coli, and their nucleotide sequences have been determined. The restriction endonuclease (ENase; R.MunI) is encoded by an open reading frame (ORF) of 606 bp, and a 699-bp ORF codes for the methyltransferase (MTase). The two genes are transcribed divergently from a 355-bp region. The gene encoding the ENase is preceded by a short co-linear ORF of 222 bp. The deduced amino acid (aa) sequence of this short ORF (SORF) closely resembles the sequences of a family of regulatory proteins that are associated with other type-II R-M systems. Comparative analysis of the deduced aa sequence of R.MunI revealed several regions of similarity to the EcoRI and RsrI ENases that recognize the GAATTC sequence. The similar mode of interaction of MunI, EcoRI and RsrI with the tetranucleotide AATT, common to the recognition sequences of these ENases, was suggested.

摘要

编码识别序列5'-CAATTG的MunI限制修饰（R-M）系统的基因已被克隆并在大肠杆菌中表达，其核苷酸序列也已确定。限制性内切酶（ENase；R.MunI）由一个606 bp的开放阅读框（ORF）编码，一个699 bp的ORF编码甲基转移酶（MTase）。这两个基因从一个355 bp的区域反向转录。编码ENase的基因之前有一个222 bp的短共线性ORF。这个短ORF（SORF）推导的氨基酸（aa）序列与与其他II型R-M系统相关的一类调节蛋白的序列非常相似。对R.MunI推导的aa序列的比较分析揭示了与识别GAATTC序列的EcoRI和RsrI ENases相似的几个区域。有人提出，MunI、EcoRI和RsrI与这些ENases识别序列共有的四核苷酸AATT的相互作用模式相似。