Template:Protein primary structure

Protein primary structure and posttranslational modifications

General

Single specific AAs

Serine/Threonine	Phosphorylation Dephosphorylation Glycosylation O-GlcNAc ADP-ribosylation
Tyrosine	Phosphorylation Dephosphorylation ADP-ribosylation Sulfation Porphyrin ring linkage Adenylylation Flavin linkage Topaquinone (TPQ) formation Detyrosination
Cysteine	Palmitoylation Prenylation
Aspartate	Succinimide formation ADP-ribosylation
Glutamate	Carboxylation ADP-ribosylation Methylation Polyglutamylation Polyglycylation
Asparagine	Deamidation Glycosylation
Glutamine	Transglutamination
Lysine	Methylation Acetylation Acylation Adenylylation Hydroxylation Ubiquitination Sumoylation ADP-ribosylation Deamination Oxidative deamination to aldehyde O-glycosylation Imine formation Glycation Carbamylation Succinylation Lactylation Propionylation Butyrylation
Arginine	Citrullination Methylation ADP-ribosylation
Proline	Hydroxylation
Histidine	Diphthamide formation Adenylylation
Tryptophan	C-mannosylation

Crosslinks between two AAs

Cysteine–Cysteine	Disulfide bond ADP-ribosylation
Methionine–Hydroxylysine	Sulfilimine bond
Lysine–Tyrosine	Lysine tyrosylquinone (LTQ) formation
Tryptophan–Tryptophan	Tryptophan tryptophylquinone (TTQ) formation

Crosslinks between three AAs

Serine–Tyrosine–Glycine	p-Hydroxybenzylidene-imidazolinone (HBI) formation (chromophore)
Histidine–Tyrosine–Glycine	4-(p-hydroxybenzylidene)-5-imidazolinone (HBI) formation (chromophore)
Alanine–Serine–Glycine	Methylidene-imidazolone (MIO) formation

Crosslinks between four AAs

Allysine–Allysine–Allysine–Lysine	Desmosine