C2H2 Zinc Finger Nucleotide Fluctuation

A C2H2 zinc finger nucleotide sequence can be expressed as a numerical sequence when each nucleotide is assigned its proton number. A resulting zinc finger numerical sequence could be investigated for its fractal dimension in terms of evolution, multiple finger structure flexibility, and 3-finger structure specificity. The ZNF714 sequence was found to have a fractal dimension higher than its evolutionary ancestor ZNF431, consistent with the recently reported evolutionary direction using traditional analysis. The ZNF91 sequence has 36 zinc fingers and their fractal dimensions form a Gaussian-like histogram, suggesting a maximal flexibility for capacity dimension. The CpG di-nucleotide percentage in the three zinc fingers of EGR1 is found to correlate with the fractal dimension while the five zinc fingers in ZFP91 separated into human-chimp and mouse-rat-dog groups. Extension of the fractal investigation to short genetic sequences is discussed.