You are more than welcome to support a Master's thesis and be a part of the qualitative and quantitative research.
https://forms.gle/NKHRGca8hzfoaZWL7
Thank you for your time and support! :)
Greetings from rainy Berlin :)
Im taking microbiology this semester and my professor described sigma factors as proteins that control large functions of the cell triggered by environmental responses that work by guiding RNA polymerases to the right gene. Does every gene require a sigma factor? Like when we did the lac operon they never mentioned it, but is it there bringing the RNA polymerase to it?
When researching this question I seem to find some seemingly conflicting answers. My textbook says, "sigma must bind to the polymerase before transcription can begin." However, another textbook says, "Without sigma, RNA polymerase will initiate transcription at a random point along the DNA." ...what the hell!?
Further troubling are these seemingly contradictory statements I also found while researching: "In [sigma's] absence, the core enzyme binds DNA indiscriminately and tightly" compared to "The core enzyme can weakly bind to any part of the DNA strand. It is the sigma-factor that recognizes the promoter region and binds strongly to it."
Any definitive answer or clarification would be appreciated. Thanks!
I didn't really understand this part of my book, so I hope someone can clarify this for me.
In prokaryotes I'm lost which is which.
Is the holoenzyme=RNA polymerase+sigma factor? Or is the holoenzyme a subunit of the RNA polymerase that recognized the promoter with the help of the sigma factor?
I'm lost. Any help is much appreciated.
