Do Operons Interfere with DNA Replication?

[Archosaur]

How do operons interfere with DNA replication, if at all?

I know, for example, that repressors can stop RNA polymerase, keeping a segment from being transcribed, but it's still replicated. How is this?
My guesses are:
A. The enzymes involved in DNA replication can run right over them.
or
B. All operons are temporarily activated during DNA replication.

Or, of course, something completely different...

Any help is appreciated!
Thanks.

 

[Quathor]

Not all operons are regulated by repressors. In other words, the absence of repressors does not automatically make an operon active. During DNA replication, the single stranded DNA is bound with single strand binding proteins, which probably prevents the RNA synthesis by RNA polymerases (even if activators and other required stuff were there to promote the synthesis).. And when the DNA polymerase has created the complementary strand, then the repressors probably are the first to bind the DNA, preventing unwanted RNA synthesis. However, it is known that even suppressed operons "leak" a bit.. So potentially some RNA synthesis may occur during DNA replication.. But I'm just speculating here since this is not my expertise.

 

[Ygggdrasil]

This question, of how the DNA replication machinery bypasses proteins bound to DNA, is an active field of research and we are still learning how the process works. It seems like DNA polymerases are able to kick the proteins off of DNA (for example see http://www.physorg.com/news185010534.html), although the details of how this occurs is not yet well understood.

Now something to keep in mind here is that it is difficult to get DNA and RNA polymerases started (both require specialized factors that bind to the DNA, open up the DNA, recruit the polymerases, and position them in order to get started), but once they get going, they are fairly efficient. Therefore, a protein that needs to block the difficult transcriptional initiation step (for example, by interfering with the proteins that recruit RNA polymerase to the DNA) will not necessarily be able use the same mechanisms to block a DNA or RNA polymerase that has already initiated.

 

[Archosaur]

Thank you both for your responses!

Yea, I do know about positive and negative inducible and repressible operons, I just dealt with repressors for simplicity's sake.

Ygggdrasil, thanks for the link!

 

[LudusRex]

Operons and DNA replication are two separate processes that occur within a cell. Operons are a group of genes that are regulated together and are involved in the production of a specific protein. On the other hand, DNA replication is the process by which a cell copies its genetic material to produce identical daughter cells.

There is no direct interference between operons and DNA replication. Operons do not affect the process of DNA replication and vice versa. However, there are some indirect ways in which operons may affect DNA replication.

One possible way is through the regulation of gene expression. Operons are controlled by regulatory elements such as repressors and activators, which can influence the rate of transcription of the genes within the operon. If an operon is repressed, it means that the genes within the operon are not actively being transcribed. This could potentially lead to a decrease in the production of proteins involved in DNA replication, which could indirectly affect the process.

Another way in which operons may indirectly affect DNA replication is through the competition for resources within the cell. Operons require certain resources, such as enzymes and nucleotides, to produce their proteins. If these resources are limited, it could potentially impact the efficiency of DNA replication, as the enzymes involved in DNA replication may not have access to enough resources to function properly.

However, it is important to note that these are just potential indirect effects and it is unlikely that operons would have a significant impact on DNA replication. The enzymes involved in DNA replication are highly specialized and efficient, and are able to navigate around any obstacles, such as repressors, in their way.

In summary, operons do not directly interfere with DNA replication, but they may indirectly affect it through their regulation of gene expression and competition for resources within the cell. Further research is needed to fully understand the potential interactions between operons and DNA replication.