Purification and characterization of CAF-I, a human cell factor required for chromatin assembly during DNA replication in vitro.
The purification and characterization of a replication-dependent chromatin assembly factor (CAF-I) from the nuclei of human cells is described. CAF-I is a multisubunit protein that, when added to a crude cytosol replication extract, promotes chromatin assembly on replicating SV40 DNA. Chromatin assembly by CAF-I requires and is coupled with DNA replication. The minichromosomes assembled de novo by CAF-I consist of correctly spaced nucleosomes containing the four core histones H2A, H2B, H3, and H4, which are supplied in a soluble form by the cytosol replication extract. Thus, by several criteria, the CAF-I-dependent chromatin assembly reaction described herein reflects the process of chromatin formation during DNA replication in vivo.
Smith
S
S
Cold Spring Harbor Laboratory, New York 11724.
Stillman
B
B
D001681:Biological Assay; D002467:Cell Nucleus / Q000032:analysis*; D002843:Chromatin / Q000648:ultrastructure*; D004247:DNA / Q000378:metabolism; D004261:DNA Replication; D006657:Histones / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008970:Molecular Weight; D009024:Morphogenesis; D009687:Nuclear Proteins / Q000302:isolation & purification*; D013539:Simian virus 40
D002843:Chromatin; D006657:Histones; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D004247:DNA