Recombinant human DNA polymerase beta/POLB protein

DNA polymerase beta, also known as POLB, belongs to the DNA polymerase type-X family. In eukaryotic cells, DNA polymerase beta (POLB) performs base excision repair (BER) required for DNA maintenance, replication, recombination, and drug resistance. POLB has two distinct domains, the larger is the polymerase domain itself, whereas a small basic N-terminal domain contains an AP lyase activity that excises the abasic sugar-phosphate residue at the strand break. POLB fills single nucleotide gaps in DNA produced by the base excision repair pathway of mammalian cells. Overexpression of POLB, as found in some human tumors, could confer an increase in spontaneous mutagenesis. Recombinant human POLB protein, fused to His-tag at N-terminus, was expressed in E. coli and purified by using conventional chromatography techniques.