1 research outputs found
DNA polymerase lambda (Pol 位), a novel eukaryotic DNA polymerase with a potential role in meiosis
A new gene (POLL) encoding a novel DNA polymerase (Pol 位) has been identified at mouse chromosome 19. Murine Pol 位, consisting of 573 amino acid residues, has a 32 % identity to Pol 尾, involved in nuclear DNA repair in eukaryotic cells. It is interesting that Pol 位 contains all the critical residues involved in DNA binding, nucleotide binding and selection, and catalysis of DNA polymerization, that are conserved in Pol 尾 and other DNA polymerases belonging to family X. Murine Pol 位, overproduced in Escherichia coli, displayed intrinsic DNA polymerase activity when assessed by in situ gel analysis. Pol 位 also conserves the critical residues of Pol 尾 required for its intrinsic deoxyribose phosphate lyase (dRPase) activity. The first 230 amino acid residues of Pol 位, that have no counterpart in Pol 尾, contain a BRCT domain, present in a variety of cell-cycle check-point control proteins responsive to DNA damage and proteins involved in DNA repair. Northern blotting, in situ hybridization analysis and immunostaining showed high levels of Pol 位 specifically expressed in testis, being developmentally regulated and mainly associated to pachytene spermatocytes. These first evidences, although indirect, suggest a potential role of Pol 位 in DNA repair synthesis associated with meiosis.This work has been granted by DGES (PB97-1192) and CAM (08.1/0044/98) to LB; CAM(08.1/0044.2/98) to AB; DGICYT (PB 95-0119), EC PL96-0183 and CAM (07/0022) to JM, and by an institutional grant from Fundaci贸n Ram贸n Areces