First up, I am NOT asking about how to search for and match regulatory elements using a database. I'm asking about how people found what to search for and match in a genome, how they built those databases. My question is,
How did people identify regulatory proteins/nucleotide elements in the first place?
Did they first find the proteins we now call transcription factors and sigma factors, or did they tamper with the genome to find the regulatory parts and then traced them to the proteins?
Is there a book on the history of research gene regulation to recommend?
Also, I tried Googling. Every site recommended one database or the other. I would be grateful too if you could tell me what should I have searched for?
I am more interested in Prokaryotes, but answers on Eukaryotes would also be welcome.
Context: I'm a freshman doing research (yep. the experience is kinda crazy for me) and I'm interested in finding regulatory elements in Mycobacterium smegmatis and its phages.