Campus Units

Biochemistry, Biophysics and Molecular Biology

Document Type

Article

Publication Version

Published Version

Publication Date

10-2013

Journal or Book Title

Biochemistry

Volume

52

Issue

44

First Page

7723

Last Page

7730

DOI

10.1021/bi400708m

Abstract

Plasmodium falciparum, a parasitic organism and one of the causative agents of malaria, contains an unusual organelle called the apicoplast. The apicoplast is a nonphotosynthetic plastid responsible for supplying the parasite with isoprenoid units and is therefore indispensable. Like mitochondria and the chloroplast, the apicoplast contains its own genome and harbors the enzymes responsible for its replication. In this report, we determine the relative probabilities of nucleotide misincorporation by the apicoplast polymerase (apPOL), examine the kinetics and sequence dependence of mismatch extension, and determine the rates of mismatch removal by the 3′ to 5′ proofreading activity of the DNA polymerase. While the intrinsic polymerase fidelity varies by >50-fold for the 12 possible nucleotide misincorporations, the most dominant selection step for overall polymerase fidelity is conducted at the level of mismatch extension, which varies by >350-fold. The efficiency of mismatch extension depends on both the nature of the DNA mismatch and the templating base. The proofreading activity of the 12 possible mismatches varies <3-fold. The data for these three determinants of polymerase-induced mutations indicate that the overall mutation frequency of apPOL is highly dependent on both the intrinsic fidelity of the polymerase and the identity of the template surrounding the potential mismatch.

Comments

Reprinted (adapted) with permission from Biochemistry 52 (2013): 7723, doi: 10.1021/bi400708m. Copyright 2013 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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