6dgd
From Proteopedia
PriA helicase bound to dsDNA of a DNA replication fork
Structural highlights
FunctionA0A1W2ITH4_KLEPN Involved in the restart of stalled replication forks. Recognizes and binds the arrested nascent DNA chain at stalled replication forks. It can open the DNA duplex, via its helicase activity, and promote assembly of the primosome and loading of the major replicative helicase DnaB onto DNA.[HAMAP-Rule:MF_00983] Publication Abstract from PubMedDNA replication restart, the essential process that reinitiates prematurely terminated genome replication reactions, relies on exquisitely specific recognition of abandoned DNA replication-fork structures. The PriA DNA helicase mediates this process in bacteria through mechanisms that remain poorly defined. We report the crystal structure of a PriA/replication-fork complex, which resolves leading-strand duplex DNA bound to the protein. Interaction with PriA unpairs one end of the DNA and sequesters the 3'-most nucleotide from the nascent leading strand into a conserved protein pocket. Cross-linking studies reveal a surface on the winged-helix domain of PriA that binds to parental duplex DNA. Deleting the winged-helix domain alters PriA's structure-specific DNA unwinding properties and impairs its activity in vivo. Our observations lead to a model in which coordinated parental-, leading-, and lagging-strand DNA binding provide PriA with the structural specificity needed to act on abandoned DNA replication forks. Structure-specific DNA replication-fork recognition directs helicase and replication restart activities of the PriA helicase.,Windgassen TA, Leroux M, Satyshur KA, Sandler SJ, Keck JL Proc Natl Acad Sci U S A. 2018 Sep 10. pii: 1809842115. doi:, 10.1073/pnas.1809842115. PMID:30201718[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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