| First Author | Domínguez O | Year | 2000 |
| Journal | EMBO J | Volume | 19 |
| Issue | 7 | Pages | 1731-42 |
| PubMed ID | 10747040 | Mgi Jnum | J:61446 |
| Mgi Id | MGI:1354997 | Doi | 10.1093/emboj/19.7.1731 |
| Citation | Dominguez O, et al. (2000) DNA polymerase mu (Pol mu), homologous to TdT, could act as a DNA mutator in eukaryotic cells. EMBO J 19(7):1731-42 |
| abstractText | A novel DNA polymerase has been identified in human cells. Human DNA polymerase mu (Pol mu), consisting of 494 amino acids, has 41% identity to terminal deoxynucleotidyltransferase (TdT). Human Pol mu, overproduced in Escherichia coli in a soluble form and purified to homogeneity, displays intrinsic terminal deoxynucleotidyltransferase activity and a strong preference for activating Mn(2+) ions. Interestingly, unlike TdT, the catalytic efficiency of polymerization carried out by Pol mu was enhanced by the presence of a template strand. Using activating Mg(2+) ions, template-enhanced polymerization was also template-directed, leading to the preferred insertion of complementary nucleotides, although with low discrimination values. In the presence of Mn(2+) ions, template-enhanced polymerization produced a random insertion of nucleotides. Northern-blotting and in situ analysis showed a preferential expression of Pol mu mRNA in peripheral lymphoid tissues. Moreover, a large proportion of the human expressed sequence tags corresponding to Pol mu, present in the databases, derived from germinal center B cells. Therefore, Pol mu is a good candidate to be the mutator polymerase responsible for somatic hyper- mutation of immunoglobulin genes. |
