A simple error-prone PCR method through dATP reduction

Abstract:

Abstract:The error-prone PCR is one of the main methods for in vitro gene mutagenesis，usually through adding Mn2+，increasing Mg2+ and dCTP/dTTP concentration．［Objective and Methods］In this study，both the antifungal protein gene Ace-AMP1 from Allium cepa and the Bt toxin gene cry1A (c) from Bacillus thuringiensis were subjected to PCR mutagenesis through reducing the dATP concentration，but without adding Mn2 + or adjusting other PCR components．［Results］The result showed that the rates of base mutation and sequence variation were increased along with the decrease of dATP concentrations． When dTTP/dCTP/dGTP:dATP equaled 20∶1－40∶1，the rate of base mutation was between 1.4% and 1.8%，and the rate of sequence variation was between 77.8%and 100%．［Discussion and Conclusion］This method is simple and practical，and enables the process optimization of several mutagenic factors in conventional errorprone PCR．Moreover，as the resulting base mutations were mainly A·T→G·C transition，the present method provides a new way to improve the GC content of gene by in vitro mutagenesis．The mutagenesis method of simply reducing single dNTP concentration could improve AT or GC content of the target gene，it is an expansion of error-prone PCR.