*  6-O-Methylguanine - Wikipedia
Yarosh DB (1985). "The role of O6-methylguanine-DNA methyltransferase in cell survival, mutagenesis and carcinogenesis". Mutat ... It base-pairs to thymine rather than cytosine, causing a G:C to A:T transition in DNA. 6-O-methylguanine is formed in DNA by ... alkylation of the oxygen atom of guanine, most often by N-nitroso compounds (NOC) and sometimes due to methylation by other ... "O6-methylguanine-DNA methyltransferase in the defense against N-nitroso compounds and colorectal cancer". Carcinogenesis. 34 ( ...
  https://en.wikipedia.org/wiki/6-O-Methylguanine
*  DNA repair - Wikipedia
May 2013). "Different patterns of DNA methylation of the two distinct O6-methylguanine-DNA methyltransferase (O6-MGMT) promoter ... is a DNA damage tolerance process that allows the DNA replication machinery to replicate past DNA lesions such as thymine ... leading to an intact DNA. MMEJ is always accompanied by a deletion, so that MMEJ is a mutagenic pathway for DNA repair. The ... and generation of DNA strand interruptions from reactive oxygen species, alkylation of bases (usually methylation), such as ...
  https://en.wikipedia.org/wiki/DNA_repair
*  molecular biology Flashcards - Cram.com
... is directly reversed by the protein methyl guanine methyl transferase (MGMT). 5. The third type of DNA damage reversed by cells ... Adjacent thymine residues are also relatively mutagenic, as they can form thymine dimers when exposed to ultraviolet light. ... Alkylation of the DNA (repairable by direct removal of the alkyl group from the base, by base excision repair, or by nucleotide ... a postreplication DNA repair system that allows DNA replication to bypass lesions or errors in the DNA. The SOS uses the RecA ...
  http://www.cram.com/flashcards/molecular-biology-447872
*  Chemical Damage to Nucleic Acids - CHEMICAL BIOLOGY
Minor photoproducts in DNA. Exposure of DNA to UV radiation also generates oxidative base damage. In particular, thymine glycol ... methylhydrazines to mutagenic methylating derivatives and inducers of the adaptive response of Escherichia coli to alkylation ... 1. Some microorganisms are endowed with a particular methyltransferase activity that catalyzes the methylation of halide ions ( ... Spontaneous DNA-DNA and DNA-Protein Crosslinks. The covalent interaction of a chemical with bases on both strands of the DNA ...
  http://schoolbag.info/chemistry/chemical_biology/120.html