LAMBDA-GAM PROTEIN INHIBITS THE HELICASE AND CHI-STIMULATED RECOMBINATION ACTIVITIES OF ESCHERICHIA-COLI RECBCD ENZYME
LAMBDA-GAM PROTEIN INHIBITS THE HELICASE AND CHI-STIMULATED RECOMBINATION ACTIVITIES OF ESCHERICHIA-COLI RECBCD ENZYME
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DOI：
10.1128/jb.173.18.5808-5821.1991
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发表时间：
1991-09-01
影响因子：
3.2
通讯作者：
MURPHY, KC
中科院分区：
文献类型：
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作者：
MURPHY, KC
从含有产生Gam的质粒的细胞中分离出Gam蛋白。 发现纯化的Gam蛋白结合RecBCD而不置换其任何亚基。 Gam被证明可以抑制RecBCD的所有已知酶活性：ATP依赖性单链和双链DNA外切核酸酶、ATP非依赖性单链核酸内切酶和ATP依赖性解旋酶。 当在体内产生时，甘抑制志激活的重组在红葡萄干杂交，但对宿主的能力，作为一个受体在共轭重组的影响不大。 这些实验表明，RecBCD具有额外的“未知”活性，其对Gam具有抗性或由Gam诱导。 此外，recD突变体中Gam的表达使宿主对UV照射敏感，表明Gam改变了RecBC（D-）的一种或多种体内活性。
The lambda-Gam protein was isolated from cells containing a Gam-producing plasmid. The purified Gam protein was found to bind to RecBCD without displacing any of its subunits. Gam was shown to inhibit all known enzymatic activities of RecBCD: ATP-dependent single- and double-stranded DNA exonucleases, ATP-independent single-stranded endonuclease, and the ATP-dependent helicase. When produced in vivo, Gam inhibited chi-activated recombination in lambda-red gam crosses but had little effect on the host's ability to act as a recipient in conjugational recombination. These experiments suggest that RecBCD possesses an additional "unknown" activity that is resistant to or induced by Gam. Additionally, the expression of Gam in recD mutants sensitizes the host to UV irradiation, indicating that Gam alters one or more of the in vivo activities of RecBC(D-).