Binding of Cys2His2 transcription factors with operator DNA: functional role of linkers between Zn-fingers

: We present an analysis of 28 linkers between Zn-domains from ten selected Cys2His2 transcription factors. Three different groups of such linkers have been revealed. Linkers of two groups are peptides when the next and preceded Zn-fingers are always bound to DNA. The linkers of the third distinctive group prevent binding of Zn-fingers to DNA. An analysis of lack of Zn-finger binding to DNA allows understanding the specific functional sense of the multiple Zn-finger structure of the factors. Moreover, such linkers give the factors performing a few additional functions. We have shown that binding of definite Zn-finger to DNA is determined by linker sequence, its residues conformation, and direction of linker vector. We have assumed that linkers can play an important role as recognition determinant at the final stage of the evolutionary selection of transcription factors.