Flashcards in Kandpal - DNA Repair Deck (32):
What are the type of mutations of repair proteins?
Homologs of mutS and mutL
What type of damages of post replcation errors?
Depurination,Deamination, UV Damage (Pyrimidine dimers), Heat, Extreme pH, Radiations, substances in environment
What are the consequences of DNA damage
DNA will have an altered sequence during next round of replication.
Survival of a cell is dependant on?
What is a transition error?
Substitution of a prryimidine with another pyrimidine or a purine with another purine.
What is transversion error?
Substitution of a pyrimidine with a purine or vice versa
What is frameshift error?
Due to addition/deletion of bases (codon)
What is the 1st level of replair during replication.
Proofreading - 3' to 5' exonuclease activity of DNA polymerase.
What removes mismatched nucleotides?
The 3' to 5' exonuclease during proofreading
What happens when replication errors are missed by proofreading activity?
Distortion in the DNA helix is recognized and repaired by strand directed mismatch repair
For a mismatched E. Coli, both stands are methylated at what junction?
What recognizes mismatched bases?
What scans the DNA where the "nick" to determine the newly replicated DNA?
What is the percentage of colon cancer cases that are familial (run in the family)?
10 to 15%
What are the 2 familial colon cancers?
HNPCC (Hereditary non-polyposis colon cancer) and FAP (Familial adenomatous polyposis)
When you remove a purine from a nucleotide, what is left over?
A base-less sugar and cytosine will convert into a uracil.
Can thymine be deamination?
NO. It has no amino group
What does 5-methyl cytosine can be deaminated?
Yes. Into thymine
Can you create a deletion in deamination?
No only in depurination.
What is base excision repair?
Specific base is removed and repaired
What is nucleotide excision repair?
A stretch of DNA is removed and a new strand with the correct base is synthesized.
What is the Yeast repair names for excision repair?
What is the Yeast repair for post-replication repair?
What is the Yeast repair for recombination -mediated repair?
DNA or RNA, what is RAD3 part _____ polymerase?
When does double strand breaks occur?
During Recombination and Ionizing radition
What 2 processes repair double strand breaks?
Homologous end joining (HEJ) and Non Homologous end joning (NHEJ)
Since BRCA1 and BRCA2 are defects in double stranded break repair, what do BRCA1 and BRCA2 stand for?
Breast Cancer gener 1 and gene 2. Predispose to both Breast and Ovarian cancer.
What is the percentage of breast cancer cases that are familial?
What is the susceptibility to breast cancer?
What is Werner Syndrome?
An Autosomal recessive disease. Causes cataracts, changing of skin conditions, short stature, premature graying, thinning of hair.