Characterization of DNA polymerase φ from Saccharomyces cerevisiae

为了分析φ聚合酶在体内的功能，构建了一种新型突变体(degron变异体)。POL5的变性突变体(pol5^<td>)在DNA聚合酶φ基因上游含有作为泛素蛋白分解系统底物的多肽。该突变株在高温(37℃)下不会在不过量产生UBC4基因产物的情况下成为致死菌株，因此该突变株还含有大量表现降解系统UBC4基因产物的质粒。利用DNA聚合酶φ的突变体pol5<td>对该突变株进行了基因芯片分析，以检测该基因在非允许温度下的表达模式，并与野生型在相同条件下的表达进行了比较。结果表明，没有获得特异的基因簇，这意味着POL5基因不是进行普遍的转录调控，而是进行特异的基因群调控。

The new type mutant (degron mutant) was constructed in order to analyze the function of DNA polymerase φ in vivo. The degron mutant of POL5 (pol5^<td>) has the peptide which is substrate of proteolysis system of the ubiquitin in the upstream of the gene of DNA polymerase φ. This mutant also has plasmid for large manifesting UBC4 gene product of the degrading system, because it did not become the lethality in the high temperature (37 degrees) without overproducing the UBC4 gene product.The DNA microarray analysis of the POL5 gene was carried out in order to examine the pattern of the gene expression at non-permissive temperature using the mutant pol5^<td> of DNA polymerase φ, and it was compared with the expression of the wild type by same condition. The result showed that the specific gene cluster peculiarly changed was not obtained.This fact means that POL5 gene carries out universal transcriptional control not but specific gene group.