[嗜酸氧化亚铁硫杆菌AIU 301的pKW301中arsR基因存在时大肠杆菌K12中I型限制的缓解]

[Alleviation of type I restriction in Escherichia coli K12 in the presence of the arsR gene from pKW301 of Acidiphilium multivorum AIU 301].

作者信息

Rastorguev S M, Zavil'gel'skiĭ G B, Suzuki K, Sakka K

出版信息

Mol Biol (Mosk). 2001 Jan-Feb;35(1):79-82.

Abstract

A study was made of the antirestriction activity of Acidiphilium multivorum AIU 301 ArsR, a repressor of the ars operon which confers resistance to arsenite and arsenate and is on pKW301. In Escherichia coli, arsR cloned under the control of Plac in a multi-copy vector alleviated restriction of nonmodified lambda DNA by a factor of 120, six times more efficiently than its analogs of conjugal plasmids R64 (incI1) and R773 (incFI). Amino acid sequence analysis showed that the three ArsR proteins have a homologous region of 38 residues, including the antirestriction motif, in their N domains, whereas the motif is in the C domain in the Ard proteins. The other regions are nonhomologous, and pKW301 ArsR is 33 residues shorter than R64 and R773 ArsRs. The total charge is -4 in pKW301 ArsR and +2 in R64 and R733 ArsRs. A total negative charge was assumed to contribute to the antirestriction activity.

摘要

对嗜酸多源菌AIU 301 ArsR的抗限制活性进行了研究，ArsR是位于pKW301上的ars操纵子的阻遏物，该操纵子赋予对亚砷酸盐和砷酸盐的抗性。在大肠杆菌中，在多拷贝载体中受Plac控制克隆的arsR使未修饰的λDNA的限制减轻了120倍，比其接合质粒R64（IncI1）和R773（IncFI）的类似物效率高6倍。氨基酸序列分析表明，这三种ArsR蛋白在其N结构域中有一个38个残基的同源区域，包括抗限制基序，而在Ard蛋白中该基序位于C结构域。其他区域是非同源的，pKW301 ArsR比R64和R773 ArsR短33个残基。pKW301 ArsR的总电荷为-4，R64和R733 ArsR的总电荷为+2。假定总负电荷有助于抗限制活性。