| Comments |
P.1106 left column bottom paragraph: "As a general outline, [investigators] present in Fig. 1 a cartoon showing how in most organisms the overall accuracy of DNA replication can be considered as the outcome of three (highly conserved) components acting sequentially: (1) selection of the correct DNA nucleotide by the replicative DNA polymerase, (2) removal of any misinserted nucleotides by the 3′→5′ exonuclease proofreading activity associated with the polymerase, and (3) postreplicative correction of polymerase errors that have escaped proofreading by the DNA mismatch repair system (MMR) (primary sources Schaaper, 1993a Kunkel & Bebenek, 2000 Kunkel, 2004 Kunkel & Bebenek, 2004). In E. coli, the mismatch repair step is performed by the mutHLS system, which is capable of distinguishing the (incorrect) newly synthesized strand from the (correct) parental strand based on the transient undermethylation (at 5′-GATC-3′ sequences) of the newly made strand (reviewed in primary sources Modrich, 1987 Kunkel & Erie, 2005). Roughly, the contribution of each of these components to the error rate can be estimated at 10^−5 (insertion), 10^−2 (proofreading), and 10^−3 (mismatch repair), accounting for the 10^−10 overall rate, although each contribution is highly dependent on the precise type of error under question (primary sources Schaaper, 1993a Kunkel & Bebenek, 2000 Kunkel, 2004)." Please note-primary source Kunkel & Bebenek, 2004 wasn't located in article |