Question About Dna

[Anchovyforestbane]

I understand the function of RNAP in DNA transcription. My question is, since RNAP copies a specific set of codons from one of the unbound nucleotides, how can it tell which nucleotide to bind to? Does it ever bind to the wrong nucleotide, and if so, what are the consequences of this?

[GAHD]

It can tell from the start/stop signals coded directly on the DNA chain. It's rather difficult to bind to a "wrong" site what with mediator complex doing what they do, but with free radicals and the brownian motion nature of it all false positives can and do happen. The result generally falls down to "tolerance" in that out of multiple billions of active molecules in the overall organism, it's "ok" for there to be some "bad read/write" operations as they'll have very little effect on the result. Either they do nothing and get excreted, or they operate "close enough" to get used somewhere. Maybe one chunk of heme has a bad oxidation state- oh well, maybe one or a couple of chains in a muscle or ligament is too strong or too weak-oh well. "Close enough" works well with distributed properties covering for each other.

 

[Anchovyforestbane]

It can tell from the start/stop signals coded directly on the DNA chain. It's rather difficult to bind to a "wrong" site what with mediator complex doing what they do, but with free radicals and the brownian motion nature of it all false positives can and do happen.

 

 

Could you tell me more about this mediator complex?