Biochemical and Structural Insights into the Winged Helix Domain of P150, the Largest Subunit of the Chromatin Assembly Factor 1

Abstract

The Chromatin Assembly Factor 1 is a heterotrimeric complex responsible for the nucleo-some assembly during DNA replication and DNA repair. In humans, the largest subunit P150 is the major actor of this process. It has been recently considered as a tumor-associated protein due to its overexpression in many malignancies. Structural and functional studies targeting P150 are still lim-ited and only scarce information about this subunit is currently available. Literature data and bio-informatics analysis assisted the identification of a stable DNA binding domain, encompassing residues from 721 to 860 of P150 within the full-length protein. This domain was recombinantly pro-duced and in vitro investigated. An acidic region modulating its DNA binding ability was also identified and characterized. Results showed similarities and differences between the P150 and its yeast homologue, namely Cac-1, suggesting that, although sharing a common biological function, the two proteins may also possess different features.