Talk:Lac repressor

Untitled
Moved from article, not encyclopedic, unless it's a noted as a particular fable in the field (which I don't think it is). --Lexor 23:33, 22 Dec 2003 (UTC)


 * Once a happy bacterium was swimming in the water. Its favorite food, glucose was everywhere. It had nothing to do but eat and swim. Then one day it swam to water where there was no glucose. It soon grew tired and hungry. But the wisdom of its ancestors came to the rescue. The ancestral memory told the little bacterium the water had plenty of lactose it could make into glucose. It was more work than just eating glucose but it was well worth the effort and the bacterium regained its strength. It swam to where it could find glucose again.

Not an enzyme
Edited first sentence. LacI is not an enzyme - it does not catalyze any chemical reaction.

This could probably use a bit of work in general (I'll see if I can put something together little by little). It seems somewhat vague for something which is the one of the first known examples of one of the fundamental concepts in biochemistry. The search for the lac crystal structure lasted for decades. I see the lac operon has a bit more detail. This article should probably not describe how the operon as a whole works, but should probably focus on the repressor itself, its structure, and how it actually works. --Rich0 02:29, Apr 25, 2005 (UTC)

Second paragraph of the Function heading is a bit misleading. The repressor protein is always produced, but doesn't always bind to the operator. There are times when the repressor dissociates from the operator through sheer chance, through protein degradation, and other factors. This leads to a small amount of the operon's genes being coded and present in the cell. This small amount then facilitates uptake and digestion of lactose, which then results in the positive feedback. — Preceding unsigned comment added by 207.250.20.44 (talk) 05:34, 12 October 2011 (UTC)

lac operon merger
See here for discussion.Alun 05:12, 3 October 2005 (UTC)

Function
This sentence is (in my opinion) not right: "This DNA binding causes the specific affinity of RNA polymerase for the promoter sequence to increase sufficiently that it cannot escape the promoter region and enter elongation, and so prevents transcription of the mRNA coding for the Lac proteins.[2]"

It never occurs in the linked paper, maybe this sentence was meant: "When the inducer is present, the repressor binds less efficiently to the operator, which allows RNA polymerase to recognize its promoter and transcribe the genes necessary for lactose utilization."

In my understanding: The lac repressor binds to the promotor-region, when it gets inactivated it dissociates and the RNA polymerase can bind (and enter elongation).

But because i am still a student i don't want to edit this article, maybe someone, who knows more about this (and has the right sources) could do that.

Thx HelgaBio (talk) 11:59, 21 December 2016 (UTC)

Regulatory domain
Is it correct that this domains binds allolactose? I here have notes, from some textbook, where the COOH terminus binds allolactose. This may be wrong, but perhaps the information on wikipedia is wrong too? Either way I think we should add more references there, simply to confirm it. 2A02:8388:1602:6D80:A584:D1E1:2690:10E6 (talk) 12:39, 15 December 2020 (UTC)