Double-Stranded Viral and Cellular DNA's as Templates for Purified Mammalian DNA-Dependent RNA Polymerases

摘要: The multiplicity and different intranuclear localizations of DNA-dependent RNA polymerases have suggested that gene expression in animal cells is regulated, at least part, by distinct with template specificities [1]. One the most direct ways to support this hypothesis would be show vitro various purified enzymes specifically transcribe parts deproteinized chromosomal DNA. A first step such a study ask whether alone can fact initiate synthesis on an intact double-stranded DNA, or presence additional initiation factor(s), similar E. coli σ factor [2, 3] (are) required. Previous studies involving normal calf thymus DNA preparations inhibitor AF/013 [4–7] AI B sites could “true” regions while enzyme lack factor. It nevertheless clear possible specificity cannot unequivocally demonstrated using these ordinary DNA’s, since all them contain high number single-stranded nicks (“high” compared expected true promoter sites), acting as efficient non-specific [8, 9].