The ins and outs of nucleosome assembly

De novo nucleosome assembly coupled to DNA replication and repair in vitro involves the histone chaperone chromatin assembly factor 1 (CAF-I). Recent studies support a model in which CAF-1 can be targeted to newly synthesized DNA through a direct interaction with proliferating cell nuclear antigen ( PCNA) and can act synergistically with a newly identified histone chaperone . Insights have also been obtained into mechanisms by which this CAF-1-depe ndent pathway can establish a repressed chromatin state.