Crosstalk between primase subunits can act to regulate primer synthesis in trans

Jacob E. Corn, Paul J. Pease, Greg L. Hura, James M. Berger

Research output: Contribution to journalArticlepeer-review

82 Scopus citations


The coordination of primase function within the replisome is an essential but poorly understood feature of lagging strand synthesis. By using crystallography and small-angle X-ray scattering (SAXS), we show that functional elements of bacterial primase transition between two dominant conformations: an extended form that uncouples a regulatory domain from its associated RNA polymerase core and a compact state that sequesters the regulatory region from the site of primer synthesis. FRET studies and priming assays reveal that the regulatory domain of one primase subunit productively associates with nucleic acid that is bound to the polymerase domain of a second protomer in trans. This intersubunit interaction allows primase to select initiation sites on template DNA and implicates the regulatory domain as a "molecular brake" that restricts primer length. Our data suggest that the replisome may cooperatively use multiple primases and this conformational switch to control initiation frequency, processivity, and ultimately, Okazaki fragment synthesis.

Original languageEnglish (US)
Pages (from-to)391-401
Number of pages11
JournalMolecular cell
Issue number3
StatePublished - Nov 11 2005
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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