Reduced expression of the isoleucine and valine enzymes in integration host factor mutants of Escherichia coli.
Reduced expression of the isoleucine and valine enzymes in integration host factor mutants of Escherichia coli.
复制标题
大肠杆菌整合宿主因子突变体中异亮氨酸和缬氨酸酶的表达减少。
DOI：
10.1016/s0022-2836(84)80024-8
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发表时间：
1984
影响因子：
5.6
通讯作者：
Freundlich,M
中科院分区：
文献类型：
--
作者：
Friden,P;Voelkel,K;Sternglanz,R;Freundlich,M
在大肠杆菌K-12的整合宿主因子突变体（himA和himD）中，由IIV BandilvGEDA操纵子指定的异亮氨酸和缬氨酸（IIV）酶的水平降低。这些菌株在基本培养基中的生长抑制可以通过ILV酶之一乙酰羟酸合酶I（AHASI）的量减少来解释。在含有高组成水平AHASI的突变株的ahimA衍生物中未发现生长抑制或AHASI活性降低。在himAstrains中观察到ILV酶和ILV特异性信使RNA的减少量之间的强相关性。这些数据表明，整合hos因子可能是其ilvBandilvGEDA操纵子转录的正效应子。
The level of the isoleucine and valine (Ilv)_enzymes specified by theilvBandilvGEDAoperons is reduced in integration host factor mutants (himAandhimD) ofEscherichia coliK-12. Growth inhibition of these strains in minimal medium can be explained by the decreased amounts of one of the Ilv enzymes, acetohydroxy acid synthase I (AHASI). No growth inhibition, or reduction in AHASI activity, was found in ahimAderivative of a mutant strain containing high constitutive levels of AHASI. A strong correlation was observed inhimAstrains between the reduced amount of the Ilv enzymes and of Ilv-specific messenger RNA. These data suggest that integration hos factor may be a positive effector for transcription of theilvBandilvGEDAoperons.