A protein that, when bound to a cis-regulatory DNA element such as an operator or an enhancer, activates transcription from an adjacent promoter.
a protein that stimulates the expression of a gene, typically by acting at a promoter to stimulate RNA polymerase
a regulatory protein that when bound to DNA, recruits RNA polymerase to a promoter and increases the rate of transcription
A gene product (usually protein) that positively regulates transcription. Activators may either increase binding of RNA polymerase to the promoter (closed complex formation) or stimulate RNA polymerase to begin transcription (open complex formation).
An activator is a DNA-binding protein that regulates one or more genes by increasing the rate of transcription. The activator may increase transcription by virtue of a connected domain which assists in the formation of the RNA polymerase holoenzyme, or may operate through a coactivator. A coactivator binds the DNA-binding activator and contains the domain assisting holoenzyme formation.