Presence of predicted transcription factor binding sites in alpha, beta and gamma papillomaviruses. Transcription factor binding sites were predicted with MATCH, using the nucleotide matricial description of each site as compiled in TRANSFAC. The coincidence levels between the binding site sequence and the sequence in the URR were fixed to minimise the number of false positives. The repertoire of transcription factor binding sites is different in different papillomaviruses. Some binding sites, such as E2, are present in most of the analysed viruses. Others are preferentially present in beta and gamma genera, such as v-Myb or FOXD3, in genus beta, such as HNF-3beta or HFH-3, or in genus gamma, such as COMP1 or GATA-3.