Kesti T, Frantti H, Syväoja J E
Department of Biochemistry, University of Oulu, Finland.
J Biol Chem. 1993 May 15;268(14):10238-45.
The cDNA encoding the catalytic polypeptide of human DNA polymerase epsilon was cloned. The deduced amino acid sequence reveals that the catalytic polypeptide is 2257 amino acids in length and its calculated molecular mass is 258 kDa. A single RNA message of 7.5 kilobases was recognized by isolated cDNA clones. The identity of the cDNA was verified by direct amino acid sequencing of tryptic fragments derived from the catalytic polypeptide of the HeLa DNA polymerase epsilon. The primary structure comparison with multiple DNA polymerases indicates that human DNA polymerase epsilon catalytic polypeptide is a homolog of the yeast Saccharomyces cerevisiae DNA polymerase II catalytic polypeptide. The proteins are 39% identical. In the region containing known DNA polymerase consensus motifs, the identity is 63%. The expression of the mRNA encoding DNA polymerase epsilon is strongly dependent on cell proliferation.
编码人DNA聚合酶ε催化多肽的cDNA被克隆出来。推导的氨基酸序列显示，该催化多肽长度为2257个氨基酸，其计算分子量为258 kDa。分离的cDNA克隆识别出一条7.5千碱基的单一RNA信息。通过对源自HeLa DNA聚合酶ε催化多肽的胰蛋白酶片段进行直接氨基酸测序，验证了cDNA的身份。与多种DNA聚合酶的一级结构比较表明，人DNA聚合酶ε催化多肽是酿酒酵母DNA聚合酶II催化多肽的同源物。这两种蛋白质的同源性为39%。在包含已知DNA聚合酶共有基序的区域，同源性为63%。编码DNA聚合酶ε的mRNA的表达强烈依赖于细胞增殖。
