Li Y, Asahara H, Patel V S, Zhou S, Linn S
Division of Biochemistry and Molecular Biology, Barker Hall, University of California, Berkeley, California 94720-3202, USA.
J Biol Chem. 1997 Dec 19;272(51):32337-44. doi: 10.1074/jbc.272.51.32337.
HeLa DNA polymerase epsilon (pol epsilon), possibly involved in both DNA replication and DNA repair, consists of a catalytic subunit of 261 kDa and a tightly bound peptide with a relative molecular mass of 55 kDa. The cDNA of the 261-kDa polypeptide has been independently cloned, sequenced, and then overexpressed in insect cells to give a soluble, but catalytically unstable protein, suggesting that the small subunit of HeLa pol epsilon might be important for stability. HeLa pol epsilon has been isolated by immunoaffinity purification to obtain sequence information which enabled the cloning of a full-length human cDNA encoding the small subunit. The clone encoded nine proteolytic peptides obtained from the subunit. The 59,434-Da predicated polypeptide has 26% identity and 44% homology to the yeast pol epsilon 80-kDa subunit, DPB2. Using fluorescence in situ hybridization, the human pol epsilon p59 locus (DPE2) was assigned to chromosome 14q13-q21.
海拉细胞DNA聚合酶ε（pol ε）可能参与DNA复制和DNA修复，它由一个261 kDa的催化亚基和一个紧密结合的相对分子质量为55 kDa的肽组成。261 kDa多肽的cDNA已被独立克隆、测序，然后在昆虫细胞中过表达，得到一种可溶但催化不稳定的蛋白质，这表明海拉细胞pol ε的小亚基可能对稳定性很重要。通过免疫亲和纯化分离出海拉细胞pol ε以获得序列信息，从而能够克隆编码该小亚基的全长人类cDNA。该克隆编码了从该亚基获得的9个蛋白水解肽段。预测的59434 Da多肽与酵母pol ε 80 kDa亚基DPB2有26%的同一性和44%的同源性。利用荧光原位杂交技术，将人类pol ε p59基因座（DPE2）定位到14号染色体q13 - q21区域。
