Topoisomerases and site-specific recombinases: similarities in structure and mechanism.

ABSTRACT: The processes of DNA topoisomerization and site-specific recombination are fundamentally similar: DNA cleavage by forming a phospho-protein covalent linkage, DNA topological rearrangement, and DNA ligation coupled with protein regeneration. Type IB DNA topoisomerases are structurally and mechanistically homologous to tyrosine recombinases. Both enzymes nick DNA double helices independent of metal ions, form 3'-phosphotyrosine intermediates, and rearrange the free 5' ends relative to the uncut strands by swiveling. In contrast, serine recombinases generate 5'-phospho-serine intermediates. A 180° relative rotation of the two halves of a 100 kDa terameric serine recombinase and DNA complex has been proposed as the mechanism of strand exchange. Here I propose an alternative mechanism. Interest

SUBMITTER: Yang W 

PROVIDER: S-EPMC6290911 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature