Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Holliday junctions are four-way branched DNA structures that are formed during recombination and by replication fork regression. Their processing depends on helicases that catalyze junction branch migration, and endonucleases that resolve the junction into nicked linear DNAs. Here we have investigated the role of a DNA binding motif called SAP in binding and resolving Holliday junctions by the fission yeast mitochondrial resolvase SpCCE1. Mutation or partial/complete deletion of the SAP motif dramatically impairs the ability of SpCCE1 to resolve Holliday junctions in a heterologous in vivo system. These mutant proteins retain the ability to recognize the junction structure and to distort it upon binding. However, once formed the mutant protein-junction complexes are relatively unstable and dissociate much faster than wild-type complexes. We show that binding stability is necessary for efficient junction resolution, and that this may be due in part to a requirement for maintaining the junction in an open conformation so that it can branch migrate to cleavable sites.

Original publication

DOI

10.1074/jbc.M302314200

Type

Journal article

Journal

J Biol Chem

Publication Date

01/08/2003

Volume

278

Pages

29121 - 29129

Keywords

Amino Acid Sequence, Binding Sites, Crystallization, DNA, DNA, Mitochondrial, Drug Stability, Endodeoxyribonucleases, Gene Deletion, Holliday Junction Resolvases, Models, Molecular, Molecular Sequence Data, Mutagenesis, Polymerase Chain Reaction, Protein Binding, Recombinant Proteins, Schizosaccharomyces, Structure-Activity Relationship