DNA pol 3 on the lagging strand?

[davcro]

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Does DNA pol3 replicate DNA between RNA primers on the lagging strand? Or does DNA pol 1, replace the primers and replicate the DNA between them? If that were the case then what would be the purpose of ligase?

 

[chiddler]

Does DNA pol3 replicate DNA between RNA primers on the lagging strand? Or does DNA pol 1, replace the primers and replicate the DNA between them? If that were the case then what would be the purpose of ligase?

i think both are true. 3 is the head honcho when it comes to DNA replication. 1 replaces RNA primers with DNA. DNA ligase seals the gap between the two.

Now that I think about it: does DNA ligase bond the primer strand to the main strand, or does it bond the primer to the complementary strand?

 

[IncognitoGuy]

Does DNA pol3 replicate DNA between RNA primers on the lagging strand? Or does DNA pol 1, replace the primers and replicate the DNA between them? If that were the case then what would be the purpose of ligase?

This gets a bit specific, but it's the answer to your question. Pol1 replaces the primers, but when it gets to the last base of the primer, there is a missing phosphate/hydroxyl connection between that last base and the rest of the DNA. This is where ligase comes in - only it can repair this tiny, tiny nick.

For the MCAT, you won't need to know this - this is more of a Biochemistry fact.

 

[MrNeuro]

This gets a bit specific, but it's the answer to your question. Pol1 replaces the primers, but when it gets to the last base of the primer, there is a missing phosphate/hydroxyl connection between that last base and the rest of the DNA. This is where ligase comes in - only it can repair this tiny, tiny nick.

For the MCAT, you won't need to know this - this is more of a Biochemistry fact.

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esentially all DNA Ligase (enzyme) does is catalyze the reaction to form a covalent phosphodiester bond between both DNA nucleotides via an ATP induced mechanism