Replication of Archaeal Chromosomes

This chapter summarizes what we know about DNA replication in archaea through the different phases of this process. The ligation of DNA ends is an essential step during the maturation process of Okazaki fragments. DNA ligase appears to be an essential protein for archaeal survival. Once again, very little is currently known about the segregation of archaeal chromosomes and their correct distribution in daughter cells. As in all organisms, after replication, the two sister chromatids are joined, requiring decatenation; in other words, the complete separation of the two chromatids. To achieve this, transient double-strand breaks are made by type II topoisomerases. Archaea possess the characteristic subtype IIB, which is capable of decatenation. However, it is possible that type IA topoisomerases, which transiently cut a single strand of DNA, are capable of separating sister chromatids during replication.