Work

Saccharomyces cerevisiae Dbf4 Has Unique Fold Necessary for Interaction with Rad53 Kinase

Year: 2011

Type: article

Abstract: Dbf4 is a conserved eukaryotic protein that functions as the regulatory subunit of the Dbf4-dependent kinase (DDK) complex. DDK plays essential roles in DNA replication initiation and checkpoint activation. During the replication checkpoint, Saccharomyces cerevisiae Dbf4 is phosphorylated in a Rad53-dependent manner, and this, in turn, inhibits initiation of replication at late origins. We have determined the minimal region of Dbf4 required for the interaction with the checkpoint kinase Rad53 and solved its crystal structure. The core of this fragment of Dbf4 folds as a BRCT domain, but it includes an additional N-terminal helix unique to Dbf4. Mutation of the residues that anchor this helix to the domain core abolish the interaction between Dbf4 and Rad53, indicating that this helix is an integral element of the domain. The structure also reveals that previously characterized Dbf4 mutants with checkpoint phenotypes destabilize the domain, indicating that its structural integrity is essential for the interaction with Rad53. Collectively, these results allow us to propose a model for the association between Dbf4 and Rad53.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.m111.233973

Authors: Lindsay A. Matthews, Darryl R. Jones, Ajai A. Prasad, Bernard P. Duncker, Alba Guarné

Institutions: McMaster University, University of Waterloo

Language: English

Topic: DNA Repair Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: Canadian Institutes of Health Research, National Institute of Biomedical Imaging and Bioengineering