The covalent or conformational alteration of one or more nucleotide sites in DNA, resulting in a change in its properties.

The addition of alkyl groups to many positions on all four bases of DNA. Alkylating agents can also modify the bases of incoming nucleotides in the course of DNA synthesis.

The covalent transfer of a methyl group to either N-6 of adenine or C-5 or N-4 of cytosine.

The repair of alkylation damage, e.g. the removal of the alkyl group at the O6-position of guanine by O6-alkylguanine-DNA alkyltransferase (AGT).

The breakdown into simpler components of DNA, deoxyribonucleic acid, one of the two main types of nucleic acid, consisting of a long unbranched macromolecule formed from one or two strands of linked deoxyribonucleotides, the 3'-phosphate group of each constituent deoxyribonucleotide being joined in 3',5'-phosphodiester linkage to the 5'-hydroxyl group of the deoxyribose moiety of the next one.

The cleavage of DNA during apoptosis, which usually occurs in two stages: cleavage into fragments of about 50 kbp followed by cleavage between nucleosomes to yield 200 bp fragments.

The conversion of N-linked glycan structures from the initially transferred oligosaccharide to a mature form, by the actions of glycosidases and glycosyltransferases. The early processing steps are conserved and play roles in glycoprotein folding and trafficking.

protein amino acid O-linked glycosylation

The formation of O-glycans by addition of glycosyl groups either to the hydroxyl group of peptidyl-serine, peptidyl-threonine, peptidyl-hydroxylysine, or peptidyl-hydroxyproline, or to the phenol group of peptidyl-tyrosine.

protein amino acid terminal glycosylation

The glycosylation of a free alpha-amino or alpha-carboxyl terminal of a peptide.

protein amino acid terminal N-glycosylation

The glycosylation of an N atom of a free alpha amino terminal of a peptide.

The covalent or non-covalent attachment of lipid moieties to an amino acid in a protein.

The covalent or non-covalent attachment of a lipid moiety to the amino terminus of a protein.