Abstract
The binding of purified mammalian RNA polymerases AI and B to Simian virus 40 (SV40) DNA was studied under various conditions (ionic strength, divalent cation, temperature) by two methods, electron microscopy and retention of enzyme · DNA complexes on nitrocellulose filters. Our studies demonstrate that there are multiple binding sites for mammalian RNA polymerases on SV40 DNA form I and that highly stable enzyme · DNA‐form‐I complexes are formed. However, in contrast to the bacterial RNA polymerase holoenzyme, the purified mammalian enzymes are unable to form a highly stable complex with a linear double‐stranded DNA (SV40 DNA form III). Our results strongly suggest that the formation of highly stable complexes between mammalian RNA polymerases and SV 40 DNA form I is due to their binding to the unpaired regions which are present in the superhelical DNA.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
