[DNA polymerases beta and lambda, and their roles in the DNA replication and repair].

One of the key stages of life of a cell is genome duplication. The main enzymes which lead this process are DNA-dependent DNA polymerases. At the moment, 19 DNA polymerases with striking properties are listed in the eukaryotic cells. Mitochondrial DNA polymerase gamma from A family and most of the nuclear enzymes from B family are high fidelity DNA polymerases which are participate in genome DNA replication process as well as in DNA repair. Among the other 1 5 proteins, the D N A polymerases belonging to the X and Y families have a special place. They participate in a different repair processes such as base excision repair and non-homologous end joining. Moreover, some of them play a specific role in the replication of the damaged DNA templates. This process is referred as translesion synthesis or TLS. The DNA polymerases beta and lambda members of X family are enclosed in polyfunctional enzymes, and their properties and functions will be discussed in this review.