Cloning and chromosomal mapping of the human DNA polymerase theta (POLQ), the eighth human DNA polymerase

We have cloned the cDNA for the eighth human DNA polymerase, DNA polymerase theta. The human cDNA encodes a putative DNA polymerase of 1762 amino acid s with a calculated molecular mass of 198 kDa. The derived protein sequence is homologous to the Drosophila melanogaster mus308 protein product, a put ative DNA polymerase-helicase involved in repair of interstrand crosslinks. The C-terminal region contains the canonical DNA polymerase motifs A, B, a nd C found in the family A type of DNA polymerases, which includes Escheric hia coli polymerase I. The N-terminal region contains a putative ATP bindin g domain but not motifs for a helicase. The gene was mapped by radiation hy brid analysis to chromosome 3q within an interval flanked by proximal marke r D3S1303 and distal marker D3S3576 and, based on proximity to a gene that has been mapped cylogenetically, within band 3q13.31. (C) 1999 Academic Pre ss.