Location of exons in DNA sequences using digital filters

A filtering technique for the location of hot spots in proteins proposed recently is applied for the location of exons in DNA sequences. The technique involves conversion of a DNA character sequence into a numerical sequence using the electron-ion interaction potential values and then filtering the numerical sequence using a narrowband bandpass digital filter whose passband is centered at the period-3 frequency, i.e., 2π/3. The strength of the bandpass-filtered signal as a function of nucleotide location is then detected using a lowpass filter. A plot of the signal power versus location reveals the presence of exons as distinct peaks. Simulations have shown that the technique leads to more accurate exon locations than another computational technique based on the short-time discrete Fourier transform. Furthermore, the amount of computation required is reduced by as much as 97 percent thereby rendering the technique suitable for the processing of long DNA sequences, even complete genomes.