DNA replication, recombination, and repair

Abstract

The instructions needed for producing all the components of a cell and for regulating their functions are encoded in the sequence of DNA. Accurate transmission of this information to the progeny and protection of the genome from chemical degradation are essential to life. Complementary base pairing in duplex DNA provides an elegant means for accurate replication of DNA and repair of DNA damage. Each strand of the duplex provides a template for generating the other strand and in essence acts as a back-up copy of the information. The many different proteins and enzymes required to physically manipulate large DNA polymers in replication, recombination, and repair, take advantage of the complementary base pairing between the strands to accomplish their tasks. These enzymes are capable of a sufficient level of accuracy to maintain genetic integrity, yet also allow a low level of mutations to generate genetic diversity ultimately allowing a population to adapt to changing conditions. Understanding how the cellular machinery functions to replicate, recombine, and repair the genome is central to understanding evolution of species and the origin of genetic diseases and cancer.