1fgu
From Proteopedia
SSDNA-BINDING DOMAIN OF THE LARGE SUBUNIT OF REPLICATION PROTEIN A
Structural highlights
Function[RFA1_HUMAN] Plays an essential role in several cellular processes in DNA metabolism including replication, recombination and DNA repair. Binds and subsequently stabilizes single-stranded DNA intermediates and thus prevents complementary DNA from reannealing.[1] [2] Functions as component of the alternative replication protein A complex (aRPA). aRPA binds single-stranded DNA and probably plays a role in DNA repair; it does not support chromosomal DNA replication and cell cycle progression through S-phase. In vitro, aRPA cannot promote efficient priming by DNA polymerase alpha but supports DNA polymerase delta synthesis in the presence of PCNA and replication factor C (RFC), the dual incision/excision reaction of nucleotide excision repair and RAD51-dependent strand exchange.[3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAlthough 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. Structure 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 EMBO J. 2001 Feb 1;20(3):612-8. PMID:11157767[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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