ROLE OF HU PROTEINS IN FORMING AND CONSTRAINING SUPERCOILS OF CHROMOSOMAL DNA IN ESCHERICHIA-COLI

被引：44

作者：

TANAKA, H ^{[1
]}

YASUZAWA, K ^{[1
]}

KOHNO, K ^{[1
]}

GOSHIMA, N ^{[1
]}

KANO, Y ^{[1
]}

SAIKI, T ^{[1
]}

IMAMOTO, F ^{[1
]}

机构：

[1] KYOTO PHARMACEUT UNIV,INST MOLEC & CELLULAR BIOL PHARMACEUT SCI,DEPT MOLEC GENET,YAMASHIMA KU,KYOTO 607,JAPAN

来源：

MOLECULAR & GENERAL GENETICS | 1995年 / 248卷 / 05期

关键词：

HU; HU-LIKE PROTEIN; DNA SUPERCOILING; DNA GYRASE;

D O I：

10.1007/BF02423446

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Induction of supercoiling in plasmid DNA by HU heterotypic and homotypic dimers, a mutant HU-2 (HupAN12), HBs and HB1 proteins with different DNA-binding affinities was investigated in vitro. The abilities of these proteins to induce supercoiling in DNA correlated with their affinities for DNA. Stoichiometrical analysis of HU heterodimers bound to DNA in the complex restraining the negative torsional tension of DNA showed that 12-13 dimers account for a single superhelical turn. The number of supercoils in the plasmid in vivo decreased on inhibition of DNA gyrase with coumermycin, reaching a steady-state level that indicated the existence of a compartment of restrained supercoils. The size of the restrained compartment was reduced in the absence of HU, indicating the participation of HU in constituting this fraction, and was larger on overproduction of HU-2 in the cells. An increased level of DNA gyrase, expressed from a plasmid carrying both gyr genes, in the cells did not compensate for the deficit of the restrained supercoils caused by HU deficiency, indicating seeming distinct and unrelated action of HU and DNA gyrase in introducing and constraining supercoiling of intracellular DNA.

引用

页码：518 / 526

页数：9

共 39 条

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