I am using ChIP- ChIP Seq for analysing Histone modification during some binding of protein directly or indirectly to a DNA. The signature of binding nucleotide sequence is often shown in terms of PWM (position weight matrix). PWM shows the probability of a nucleotide at a position in sequence if it binds to a transcription factor. So I am searching for some curated Transcription factors to do a comparative study for the same. can any one suggest me any curated repository. I have already gone through TRANSFAC. do you recommend any other database.