2au3

From Proteopedia

Revision as of 06:15, 21 November 2007

Crystal Structure of the Aquifex aeolicus primase (Zinc Binding and RNA Polymerase Domains)

Overview

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.

About this Structure

2AU3 is a Single protein structure of sequence from Aquifex aeolicus with ZN as ligand. Full crystallographic information is available from OCA.

Reference

Crosstalk between primase subunits can act to regulate primer synthesis in trans., Corn JE, Pease PJ, Hura GL, Berger JM, Mol Cell. 2005 Nov 11;20(3):391-401. PMID:16285921

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