The current invention relates to methods of targeted genetic alteration in cells, preferably plant cells, as well as to plant cells and plants thus obtained using at least a fusion protein comprising a site-specific nuclease domain and a deaminase domain, or a construct encoding the same. The method also provides for a composition and a kit comprising a combination of a first fusion protein comprising a cytosine deaminase domain and a second fusion protein comprising an adenine deaminase domain, preferably for use in the method of the invention. The method provides for targeted alteration of a DNA duplex in plant cells with increased efficacy.
