DNA Mismatch Repair: Distinguishing Faulty Daughter Strands

  • Thread starter Thread starter weng cheong
  • Start date Start date
  • Tags Tags
    dna
Click For Summary
SUMMARY

The discussion centers on the mechanism of DNA mismatch repair, specifically how methylation distinguishes between parental and daughter strands during DNA replication. Methylation occurs in newly synthesized DNA, making it hemimethylated, which allows GATC endonuclease and GATC exonuclease to identify and nick mismatched nucleotides. The conversation highlights the importance of methylation in differentiating faulty daughter strands from normal ones, emphasizing that without methylation, enzymes cannot determine which strand is correct. The context of the discussion includes both bacterial (6-adenine) and mammalian (5-cytosine) methylation systems.

PREREQUISITES
  • Understanding of DNA replication mechanisms
  • Knowledge of methylation processes in bacteria and mammals
  • Familiarity with GATC endonuclease and GATC exonuclease functions
  • Basic concepts of DNA structure and double helix distortion
NEXT STEPS
  • Research the role of hemimethylation in DNA mismatch repair
  • Study the differences between bacterial and mammalian methylation systems
  • Learn about the mechanisms of GATC endonuclease and GATC exonuclease
  • Explore the implications of DNA double helix distortion on repair processes
USEFUL FOR

Geneticists, molecular biologists, and researchers focused on DNA repair mechanisms and methylation processes in both bacterial and mammalian systems.

weng cheong
Messages
22
Reaction score
0
i understand that methylation helps to differentiate between parental strand and daughter strand with mismatch nucleotides. (newly synthesised DNA is hemimethylated)
then GATC endonuclease and GATC exonuclease will nick the mismatch nucleotide sequences.

however, i don't understand how the faulty daughter strand are distinguished from normal daughter strand?
 
Biology news on Phys.org
What is recognised is the mismatch surely? A distortion of the normal DNA double helix.

What text are you working from and does it not say that somewhere?

And is it talking about a bacterial system (6-adenine) or mammalian (5-cytosine) methylation system?

If there is a mismatch the enzymes could not distinguish which strand was 'right' i,e, parental and which 'wrong' i.e. daughter without the methylation.
 
Last edited:
In DNA replication you start out with one double stranded DNA consisting of two parental strands. After replication, you have two double stranded DNA and each of these DNA molecules contains one parental strand connected to one daughter strand. Therefore, you don't need to distinguish between daughter strands as they are on different molecules of DNA.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
4K
Replies
12
Views
3K
  • · Replies 1 ·
Replies
1
Views
9K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 1 ·
Replies
1
Views
6K
  • · Replies 10 ·
Replies
10
Views
13K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
20
Views
3K
  • · Replies 3 ·
Replies
3
Views
7K