Download MendeleyStructure of the major single-stranded DNA-binding domain of replication protein A suggests a dynamic mechanism for DNA binding.
Bochkareva, E., Belegu, V., Korolev, S., Bochkarev, A.(2001) EMBO J 20: 612-618
- PubMed: 11157767
- DOI: https://doi.org/10.1093/emboj/20.3.612
- Primary Citation of Related Structures:
1FGU - PubMed Abstract:
Although structures of single-stranded (ss)DNA-binding proteins (SSBs) have been reported with and without ssDNA, the mechanism of ssDNA binding in eukarya remains speculative. Here we report a 2.5 Angstroms structure of the ssDNA-binding domain of human replication protein A (RPA) (eukaryotic SSB), for which we previously reported a structure in complex with ssDNA. A comparison of free and bound forms of RPA revealed that ssDNA binding is associated with a major reorientation between, and significant conformational changes within, the structural modules--OB-folds--which comprise the DNA-binding domain. Two OB-folds, whose tandem orientation was stabilized by the presence of DNA, adopted multiple orientations in its absence. Within the OB-folds, extended loops implicated in DNA binding significantly changed conformation in the absence of DNA. Analysis of intermolecular contacts suggested the possibility that other RPA molecules and/or other proteins could compete with DNA for the same binding site. Using this mechanism, protein-protein interactions can regulate, and/or be regulated by DNA binding. Combined with available biochemical data, this structure also suggested a dynamic model for the DNA-binding mechanism.
Organizational Affiliation:
Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC-466, Oklahoma City, OK 73190, USA.
