Transcription Factor

In the field of molecular biology, a transcription factor (sometimes called a sequence-specific DNA binding factor) is a protein that binds to specific parts of DNA using DNA binding domains and is part of the system that controls the transfer (or transcription) of genetic information from DNA to RNA.
Transcription factors perform this function alone, or by using other proteins in a complex, by increasing (as an activator), or preventing (as a repressor) the presence of RNA polymerase, the enzyme which activates the transcription of genetic information from DNA to RNA.