The p150 and p60 subunits of chromatin assembly factor I: a molecular link between newly synthesized histones and DNA replication.

Chromatin assembly factor I (CAF-I) from human cell nuclei is a three-subunit protein complex that assembles histone octamers onto replicating DNA in a cell-free system. Sequences of cDNAs encoding the two largest CAF-I subunits reveal that the p150 protein contains large clusters of charged residues, whereas p60 contains WD repeats. p150 and p60 directly interact and are both required for DNA replication-dependent assembly of nucleosomes. Deletion of the p60-binding domain from the p150 protein prevents chromatin assembly. p150 and p60 form complexes with newly synthesized histones H3 and acetylated H4 in human cell extracts, suggesting that such complexes are intermediates between histone synthesis and assembly onto replicating DNA.