Recombinogenic activity of chimeric recA genes (Pseudomonas aeruginosa/Escherichia coli): a search for RecA protein regions responsible for this activity.
Recombinogenic activity of chimeric recA genes (Pseudomonas aeruginosa/Escherichia coli): a search for RecA protein regions responsible for this activity.
复制标题
嵌合recA基因（铜绿假单胞菌/大肠杆菌）的重组活性：寻找负责该活性的RecA蛋白区域。
DOI：
10.1093/genetics/159.1.7
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发表时间：
2001
期刊：
影响因子：
3.3
通讯作者：
Lanzov,VA
中科院分区：
文献类型：
--
作者：
Bakhlanova,IV;Ogawa,T;Lanzov,VA
在弱的，如果有的话，组成SOS功能的背景下，RecA从铜绿假单胞菌（RecAPa）显示出更高的频率的重组交换（FRE）每DNA单位长度相比，RecA从大肠杆菌（RecAEc）。为了理解这一观察结果的分子基础，并确定RecAPa多肽的哪些区域负责这种不寻常的活性，我们分析了recA E和recAPa基因之间的recAX嵌合体。我们选择了31个先前描述的重组和修复proficientrecAX杂种，并确定其FRE计算的连锁频率数据和组成SOS功能表达，通过使用thelacZ基因的SOS调控启动子的控制下测量。相对于recAEc，recAPa的FRE是recAEc的6.5倍; recAX基因的FRE的相对改变从~0.6到9.0不等。FRE增加和组成性SOS功能之间没有定量相关性。嵌合RecAX蛋白相关对中的单取代（[L29 M]或[I102 D]）、双取代（[G136 N，V142 I]）和多取代显著改变了它们的相对FRE值。N-末端和中央，但不是C-末端的蛋白质结构域内的RecA分子的三个独立的区域的残基含量也影响FRE值。这些区域中的关键氨基酸位于靠近先前确定的序列，其包括RecA聚合物中亚基相互作用的两个表面。我们认为，亚基之间的相互作用的强度是一个关键因素，在确定FRE促进RecA在体内。
In the background of weak, if any, constitutive SOS function, RecA fromPseudomonas aeruginosa(RecAPa) shows a higher frequency of recombination exchange (FRE) per DNA unit length as compared to RecA fromEscherichia coli(RecAEc). To understand the molecular basis for this observation and to determine which regions of the RecAPa polypeptide are responsible for this unusual activity, we analyzedrecAXchimeras between therecAEcandrecAPagenes. We chose 31 previously described recombination- and repair-proficientrecAXhybrids and determined their FRE calculated from linkage frequency data and constitutive SOS function expression as measured by using thelacZgene under control of an SOS-regulated promoter. Relative torecAEc, the FRE ofrecAPawas 6.5 times greater; the relative alterations of FRE forrecAXgenes varied from ~0.6 to 9.0. No quantitative correlation between the FRE increase and constitutive SOS function was observed. Single ([L29M] or [I102D]), double ([G136N, V142I]), and multiple substitutions in related pairs of chimeric RecAX proteins significantly altered their relative FRE values. The residue content of three separate regions within the N-terminal and central but not the C-terminal protein domains within the RecA molecule also influenced the FRE values. Critical amino acids in these regions were located close to previously identified sequences that comprise the two surfaces for subunit interactions in the RecA polymer. We suggest that the intensity of the interactions between the subunits is a key factor in determining the FRE promoted by RecAin vivo.