MindMap of DNA Mutagenicity, Damage and Repair (MCB2023)

- Hydroxylamine (NH2OH)
- Reacts with C (hydroxylation)
- Hydroxylated C pairs with A (CG-TA transition)
- Alkylating agents:
- Transfer alkyl groups (methyl, ethyl) to bases
- Alkylation of guanine results in
9-methylguanine (AlkG)
- AlkG pairs with T (GC ? TA transition)




- Cause inaccurate base paring
- Sometimes used in cancer and anti-viral therapy
- Adenine analogue = 2 amino purine (2AP)
- Substitutes A, (causing AT-GC transition) and
base pairs with C
- Thymine analogue = 5 Bromouracil (5BU)
- Substitutes T, (causing AT-GC transition ) and
base pairs with G


- Bases typically exist in the amino/
but can take on either imino or en
- Tautomeric forms allow for transiti
mutations to occur.
- Can occur via changes of pH




Tautomerism


- Loss of purines -> apurinic sites Insertion of DNA via
- Apurinic site don't base pair normally & Mobile Genetic
DNA Pol may insert wrong base Elements
- = Transition or Transversion after replication
or deletion
- Base loss results in ?ring opening?in the
sugar moiety causing weaking of the DNA
Depurination
backbone = strand breaks.
- Typically 1 in 105 purines are lost from DNA
every 24 hours

- Information on the DNA strand is not