3b39: Difference between revisions
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caption="3b39, resolution 2.35Å" /> | caption="3b39, resolution 2.35Å" /> | ||
'''Structure of the DnaG primase catalytic domain bound to ssDNA'''<br /> | '''Structure of the DnaG primase catalytic domain bound to ssDNA'''<br /> | ||
==Overview== | |||
Primases are essential RNA polymerases required for the initiation of DNA replication, lagging strand synthesis and replication restart. Many aspects of primase function remain unclear, including how the enzyme associates with a moving nucleic acid strand emanating from a helicase and orients primers for handoff to replisomal components. Using a new screening method to trap transient macromolecular interactions, we determined the structure of the Escherichia coli DnaG primase catalytic domain bound to single-stranded DNA. The structure reveals an unanticipated binding site that engages nucleic acid in two distinct configurations, indicating that it serves as a nonspecific capture and tracking locus for template DNA. Bioinformatic and biochemical analyses show that this evolutionarily constrained region enforces template polarity near the active site and is required for primase function. Together, our findings reverse previous proposals for primer-template orientation and reconcile disparate studies to re-evaluate replication fork organization. | |||
==About this Structure== | ==About this Structure== | ||
3B39 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3B39 OCA]. | 3B39 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3B39 OCA]. | ||
==Reference== | |||
Identification of a DNA primase template tracking site redefines the geometry of primer synthesis., Corn JE, Pelton JG, Berger JM, Nat Struct Mol Biol. 2008 Feb;15(2):163-9. Epub 2008 Jan 13. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18193061 18193061] | |||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: zinc-finger]] | [[Category: zinc-finger]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Feb 27 07:48:31 2008'' | ||
Revision as of 08:48, 27 February 2008
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Structure of the DnaG primase catalytic domain bound to ssDNA
OverviewOverview
Primases are essential RNA polymerases required for the initiation of DNA replication, lagging strand synthesis and replication restart. Many aspects of primase function remain unclear, including how the enzyme associates with a moving nucleic acid strand emanating from a helicase and orients primers for handoff to replisomal components. Using a new screening method to trap transient macromolecular interactions, we determined the structure of the Escherichia coli DnaG primase catalytic domain bound to single-stranded DNA. The structure reveals an unanticipated binding site that engages nucleic acid in two distinct configurations, indicating that it serves as a nonspecific capture and tracking locus for template DNA. Bioinformatic and biochemical analyses show that this evolutionarily constrained region enforces template polarity near the active site and is required for primase function. Together, our findings reverse previous proposals for primer-template orientation and reconcile disparate studies to re-evaluate replication fork organization.
About this StructureAbout this Structure
3B39 is a Protein complex structure of sequences from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Identification of a DNA primase template tracking site redefines the geometry of primer synthesis., Corn JE, Pelton JG, Berger JM, Nat Struct Mol Biol. 2008 Feb;15(2):163-9. Epub 2008 Jan 13. PMID:18193061
Page seeded by OCA on Wed Feb 27 07:48:31 2008