RNA polymerase II transcription regulator complex upstream stimulatory factor complex USF complex GO:1990378 cellular_component 2014-05-07T15:41:42Z USF1-USF2 heterodimer USF2 homodimer A protein complex capable of sequence-specific DNA binding RNA polymerase II transcription factor activity through binding to a symmetrical DNA sequence (E-boxes) (5'-CACGTG-3'). Found in a variety of viral and cellular promoters. bhm USF1 homodimer An example of this is USF1 in human (UniProt symbol P22415) in PMID:8576131 (inferred from direct assay).