Electron microscopic localization of DNA-dependent RNA polymerase binding sites on DNA using enzyme immobilized on colloidal gold

DNA dependent RNA polymerase has been coupled to gold granules of 60 A. The gold-polymerase complex (Au-P) has been demonstrated to bind to chick oviduct DNA and be capable of transcription as monitored by both biochemical activity and electron microscopy. Binding of Au-P to DNA is competable with free polymerase.