Myricetin inhibits Escherichia coli DnaB helicase but not primase

Authors

Mark A. Griep, University of Nebraska-LincolnFollow
Sheldon Blood, University of Nebraska - Lincoln
Marilynn A. Larson, University of Nebraska Medical Center, Omaha, Nebraska
Scott A. Koepsell, University of Nebraska Medical Center, Omaha, Nebraska
Steven H. Hinrichs, University of Nebraska Medical CenterFollow

Date of this Version

11-15-2007

Comments

Published in Bioorganic & Medicinal Chemistry 15:22 (November 15, 2007), pp. 7203-7208. Copyright © 2007 Elsevier Ltd. Used by permission. http://www.sciencedirect.com/science/journal/09680896

Abstract

Primase and DnaB helicase play central roles during DNA replication initiation and elongation. Both enzymes are drug targets because they are essential, persistent among bacterial genomes, and have different sequences than their eukaryotic equivalents. Myricetin is a ubiquitous natural product in plants that is known to inhibit a variety of DNA polymerases, RNA polymerases, reverse transcriptases, and telomerases in addition being able to inhibit kinases and helicases. We have shown that myricetin inhibits Escherichia coli DnaB helicase according to a mechanism dominated by noncompetitive behavior with a K_i of 10.0 ± 0.5 μM. At physiological ATP concentration, myricetin inhibits E. coli DnaB helicase with an inhibitory concentration at 50% maximal (IC₅₀) of 11.3 ± 1.6 μM. In contrast, myricetin inhibited E. coli primase at least 60- fold weaker than DnaB helicase and far weaker than any other polymerase.