targeting g with tal effectors a comparison of activities of talens constructed with nn and nk repeat variable di-residues针对g tal效应器比较取得活动构造与nn和nk di-residues重复变量.pdfVIP

Targeting G with TAL Effectors: A Comparison of Activities of TALENs Constructed with NN and NK Repeat Variable Di-Residues 1 1 1 1 1 Michelle L. Christian , Zachary L. Demorest , Colby G. Starker , Mark J. Osborn , Michael D. Nyquist , 1 2 3 4 1 Yong Zhang , Daniel F. Carlson , Philip Bradley , Adam J. Bogdanove , Daniel F. Voytas * 1 Department of Genetics, Cell Biology Development and Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, United States of America, 2 Department of Animal Science, University of Minnesota, Saint Paul, Minnesota, United States of America, 3 Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America, 4 Department of Plant Pathology, Iowa State University, Ames, Iowa, United States of America Abstract The DNA binding domain of Transcription Activator-Like (TAL) effectors can easily be engineered to have new DNA sequence specificities. Consequently, engineered TAL effector proteins have become important reagents for manipulating genomes in vivo. DNA binding by TAL effectors is mediated by arrays of 34 amino acid repeats. In each repeat, one of two amino acids (repeat variable di-residues, RVDs) contacts a base in the DNA target. RVDs with specificity for C, T and A have been described; however, among RVDs that target G, the RVD NN also binds A, and NK is rare among naturally occurring TAL effectors. Here we show that TAL effector nucleases (TALENs) made with NK to specify G have less activity than their NN-containing counterparts: fourteen of fifteen TALEN pairs made with NN showed more ac