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{{short description|Chemical changes in proteins following their translation from mRNA}}File:Insulin path.svg|right|thumb|upright=1.35|Post-translational modification of insulin. At the top, the ribosome translates a mRNA sequence into a protein, insulin, and passes the protein through the endoplasmic reticulum, where it is cut, folded, and held in shape by disulfide (-S-S-) bonds. Then the protein passes through the golgi apparatusgolgi apparatusIn molecular biology, post-translational modification (PTM) is the covalent process of changing proteins following protein biosynthesis. PTMs may involve enzymes or occur spontaneously. Proteins are created by ribosomes, which translate mRNA into polypeptide chains, which may then change to form the mature protein product. PTMs are important components in cell signalling, as for example when prohormones are converted to hormones.Post-translational modifications can occur on the amino acid side chains or at the protein's C- or N- termini.BOOK, Pratt, Charlotte W., Charlotte W. Pratt, Judith G. Voet, Donald Voet, Judith G., Voet, Voet, Donald,weblink Fundamentals of Biochemistry: Life at the Molecular Level, 2006, Wiley, Hoboken, NJ, 1280801548, 9780471214953, 13 July 2012,weblink 2nd, They can expand the chemical set of the 22 amino acids by changing an existing functional group or adding a new one such as phosphate. Phosphorylation is highly effective for controlling the enzyme activity and is the most common change after translation. JOURNAL, Khoury GA, Baliban RC, Floudas CA, Christodoulos Floudas, September 2011, Proteome-wide post-translational modification statistics: frequency analysis and curation of the swiss-prot database, Scientific Reports, 1, 90, 2011NatSR...1E..90K, 10.1038/srep00090, 3201773, 22034591, Many eukaryotic and prokaryotic proteins also have carbohydrate molecules attached to them in a process called glycosylation, which can promote protein folding and improve stability as well as serving regulatory functions. Attachment of lipid molecules, known as lipidation, often targets a protein or part of a protein attached to the cell membrane.Other forms of post-translational modification consist of cleaving peptide bonds, as in processing a propeptide to a mature form or removing the initiator methionine residue. The formation of disulfide bonds from cysteine residues may also be referred to as a post-translational modification.BOOK, Lodish H, Berk A, Zipursky SL, etal, 17.6, Post-Translational Modifications and Quality Control in the Rough ER, Molecular Cell Biology, 2000, W. H. Freeman, New York, 978-0-7167-3136-8, 4th,weblinkweblink For instance, the peptide hormone insulin is cut twice after disulfide bonds are formed, and a propeptide is removed from the middle of the chain; the resulting protein consists of two polypeptide chains connected by disulfide bonds.Some types of post-translational modification are consequences of oxidative stress. Carbonylation is one example that targets the modified protein for degradation and can result in the formation of protein aggregates.JOURNAL, Dalle-Donne I, Aldini G, Carini M, Colombo R, Rossi R, Milzani A, 2006, Protein carbonylation, cellular dysfunction, and disease progression, Journal of Cellular and Molecular Medicine, 10, 2, 389–406, 10.1111/j.1582-4934.2006.tb00407.x, 3933129, 16796807, JOURNAL, Grimsrud PA, Xie H, Griffin TJ, Bernlohr DA, August 2008, Oxidative stress and covalent modification of protein with bioactive aldehydes, The Journal of Biological Chemistry, 283, 32, 21837–41, 10.1074/jbc.R700019200, 2494933, 18445586, free, Specific amino acid modifications can be used as biomarkers indicating oxidative damage.JOURNAL, Gianazza E, Crawford J, Miller I, Detecting oxidative post-translational modifications in proteins, Amino Acids, 33, 1, 51–6, July 2007, 17021655, 10.1007/s00726-006-0410-2, 23819101, Sites that often undergo post-translational modification are those that have a functional group that can serve as a nucleophile in the reaction: the hydroxyl groups of serine, threonine, and tyrosine; the amine forms of lysine, arginine, and histidine; the thiolate anion of cysteine; the carboxylates of aspartate and glutamate; and the N- and C-termini. In addition, although the amide of asparagine is a weak nucleophile, it can serve as an attachment point for glycans. Rarer modifications can occur at oxidized methionines and at some methylene groups in side chains.BOOK, Walsh, Christopher T., Posttranslational modification of proteins : expanding nature's inventory, 2006, Roberts and Co. Publ., Englewood, 9780974707730, {{rp|12–14}}Post-translational modification of proteins can be experimentally detected by a variety of techniques, including mass spectrometry, Eastern blotting, and Western blotting. Additional methods are provided in the #External links section.

PTMs involving addition of functional groups

Addition by an enzyme in vivo

Hydrophobic groups for membrane localization

• myristoylation (a type of acylation), attachment of myristate, a C14 saturated acid
• palmitoylation (a type of acylation), attachment of palmitate, a C16 saturated acid
• isoprenylation or prenylation, the addition of an isoprenoid group (e.g. farnesol and geranylgeraniol)
  • farnesylation
  • geranylgeranylation
• glypiation, glycosylphosphatidylinositol (GPI) anchor formation via an amide bond to C-terminal tail

Cofactors for enhanced enzymatic activity

• lipoylation (a type of acylation), attachment of a lipoate (C8) functional group
• flavin moiety (FMN or FAD) may be covalently attached
• heme C attachment via thioether bonds with cysteines
• phosphopantetheinylation, the addition of a 4'-phosphopantetheinyl moiety from coenzyme A, as in fatty acid, polyketide, non-ribosomal peptide and leucine biosynthesis
• retinylidene Schiff base formation

Modifications of translation factors

• diphthamide formation (on a histidine found in eEF2)
• ethanolamine phosphoglycerol attachment (on glutamate found in eEF1α)JOURNAL, Whiteheart SW, Shenbagamurthi P, Chen L, Cotter RJ, Hart GW, Murine elongation factor 1 alpha (EF-1 alpha) is posttranslationally modified by novel amide-linked ethanolamine-phosphoglycerol moieties. Addition of ethanolamine-phosphoglycerol to specific glutamic acid residues on EF-1 alpha, The Journal of Biological Chemistry, 264, 24, 14334–41, August 1989, 10.1016/S0021-9258(18)71682-7, 2569467, etal, free,
• hypusine formation (on conserved lysine of eIF5A (eukaryotic) and aIF5A (archaeal))
• beta-Lysine addition on a conserved lysine of the elongation factor P (EFP) in most bacteria.JOURNAL, Roy H, Zou SB, Bullwinkle TJ, Wolfe BS, Gilreath MS, Forsyth CJ, Navarre WW, Ibba M, The tRNA synthetase paralog PoxA modifies elongation factor-P with (R)-β-lysine, Nature Chemical Biology, 7, 10, 667–9, August 2011, 21841797, 3177975, 10.1038/nchembio.632, EFP is a homolog to eIF5A (eukaryotic) and aIF5A (archaeal) (see above).

Smaller chemical groups

• acylation, e.g. O-acylation (esters), N-acylation (amides), S-acylation (thioesters)
  • acetylation, the addition of an acetyl group, either at the N-terminus of the protein or at lysine residues.JOURNAL, Ali I, Conrad RJ, Verdin E, Ott M, Lysine Acetylation Goes Global: From Epigenetics to Metabolism and Therapeutics, Chem Rev, 118, 3, 1216–1252, February 2018, 29405707, 6609103, 10.1021/acs.chemrev.7b00181, The reverse is called deacetylation.
  • formylation
• alkylation, the addition of an alkyl group, e.g. methyl, ethyl
  • methylation the addition of a methyl group, usually at lysine or arginine residues. The reverse is called demethylation.
• amidation at C-terminus. Formed by oxidative dissociation of a C-terminal Gly residue.JOURNAL, Bradbury AF, Smyth DG, Peptide amidation, Trends in Biochemical Sciences, 16, 3, 112–5, March 1991, 2057999, 10.1016/0968-0004(91)90044-v,
• amide bond formation
  • amino acid addition
    • arginylation, a tRNA-mediation addition
    • polyglutamylation, covalent linkage of glutamic acid residues to the N-terminus of tubulin and some other proteins.JOURNAL, Eddé B, Rossier J, Le Caer JP, Desbruyères E, Gros F, Denoulet P, Posttranslational glutamylation of alpha-tubulin, Science, 247, 4938, 83–5, January 1990, 1967194, 10.1126/science.1967194, 1990Sci...247...83E, (See tubulin polyglutamylase)
    • polyglycylation, covalent linkage of one to more than 40 glycine residues to the tubulin C-terminal tail
• butyrylation
• gamma-carboxylation dependent on Vitamin KJOURNAL, Walker CS, Shetty RP, Clark K, Kazuko SG, Letsou A, Olivera BM, Bandyopadhyay PK, On a potential global role for vitamin K-dependent gamma-carboxylation in animal systems. Evidence for a gamma-glutamyl carboxylase in Drosophila, The Journal of Biological Chemistry, 276, 11, 7769–74, March 2001, 11110799, 10.1074/jbc.M009576200, etal, free,
• glycosylation, the addition of a glycosyl group to either arginine, asparagine, cysteine, hydroxylysine, serine, threonine, tyrosine, or tryptophan resulting in a glycoprotein. Distinct from glycation, which is regarded as a nonenzymatic attachment of sugars.
  • O-GlcNAc, addition of N-acetylglucosamine to serine or threonine residues in a β-glycosidic linkage
  • polysialylation, addition of polysialic acid, PSA, to NCAM
• malonylation
• hydroxylation: addition of an oxygen atom to the side-chain of a Pro or Lys residue
• iodination: addition of an iodine atom to the aromatic ring of a tyrosine residue (e.g. in thyroglobulin)
• nucleotide addition such as ADP-ribosylation
• phosphate ester (O-linked) or phosphoramidate (N-linked) formation
  • phosphorylation, the addition of a phosphate group, usually to serine, threonine, and tyrosine (O-linked), or histidine (N-linked)
  • adenylylation, the addition of an adenylyl moiety, usually to tyrosine (O-linked), or histidine and lysine (N-linked)
  • uridylylation, the addition of an uridylyl-group (i.e. uridine monophosphate, UMP), usually to tyrosine
• propionylation
• pyroglutamate formation
• S-glutathionylation
• S-nitrosylation
• S-sulfenylation (aka S-sulphenylation), reversible covalent addition of one oxygen atom to the thiol group of a cysteine residueJOURNAL, Chung HS, Wang SB, Venkatraman V, Murray CI, Van Eyk JE, Cysteine oxidative posttranslational modifications: emerging regulation in the cardiovascular system, Circulation Research, 112, 2, 382–92, January 2013, 23329793, 4340704, 10.1161/CIRCRESAHA.112.268680, 1,

• S-sulfinylation, normally irreversible covalent addition of two oxygen atoms to the thiol group of a cysteine residue
• S-sulfonylation, normally irreversible covalent addition of three oxygen atoms to the thiol group of a cysteine residue, resulting in the formation of a cysteic acid residue
• succinylation addition of a succinyl group to lysine
• sulfation, the addition of a sulfate group to a tyrosine.

Non-enzymatic modifications in vivo

Examples of non-enzymatic PTMs are glycation, glycoxidation, nitrosylation, oxidation, succination, and lipoxidation."The Advanced Lipoxidation End-Product Malondialdehyde-Lysine in Aging and Longevity" PMID 33203089 PMC7696601

• glycation, the addition of a sugar molecule to a protein without the controlling action of an enzyme.
• carbamylation the addition of Isocyanic acid to a protein's N-terminus or the side-chain of Lys.JOURNAL, Jaisson S, Pietrement C, Gillery P, Carbamylation-derived products: bioactive compounds and potential biomarkers in chronic renal failure and atherosclerosis, Clinical Chemistry, 57, 11, 1499–505, November 2011, 21768218, 10.1373/clinchem.2011.163188, free,
• carbonylation the addition of carbon monoxide to other organic/inorganic compounds.
• spontaneous isopeptide bond formation, as found in many surface proteins of Gram-positive bacteria.JOURNAL, Kang HJ, Baker EN, Intramolecular isopeptide bonds: protein crosslinks built for stress?, Trends in Biochemical Sciences, 36, 4, 229–37, April 2011, 21055949, 10.1016/j.tibs.2010.09.007,

Non-enzymatic additions in vitro

• biotinylation: covalent attachment of a biotin moiety using a biotinylation reagent, typically for the purpose of labeling a protein.
• carbamylation: the addition of Isocyanic acid to a protein's N-terminus or the side-chain of Lys or Cys residues, typically resulting from exposure to urea solutions.JOURNAL, Stark GR, Stein WH, Moore X, Reactions of the Cyanate Present in Aqueous Urea with Amino Acids and Proteins, J Biol Chem, 235, 11, 3177–3181, 1960, 10.1016/S0021-9258(20)81332-5, free,
• oxidation: addition of one or more Oxygen atoms to a susceptible side-chain, principally of Met, Trp, His or Cys residues. Formation of disulfide bonds between Cys residues.
• pegylation: covalent attachment of polyethylene glycol (PEG) using a pegylation reagent, typically to the N-terminus or the side-chains of Lys residues. Pegylation is used to improve the efficacy of protein pharmaceuticals.

Conjugation with other proteins or peptides

• ubiquitination, the covalent linkage to the protein ubiquitin.
• SUMOylation, the covalent linkage to the SUMO protein (Small Ubiquitin-related MOdifier)Van G. Wilson (Ed.) (2004). Sumoylation: Molecular Biology and Biochemistry {{webarchive|url=https://web.archive.org/web/20050209075122weblink |date=2005-02-09 }}. Horizon Bioscience. {{ISBN|0-9545232-8-8}}.
• neddylation, the covalent linkage to the Nedd protein
• ISGylation, the covalent linkage to the ISG15 protein (Interferon-Stimulated Gene 15)JOURNAL, Malakhova OA, Yan M, Malakhov MP, Yuan Y, Ritchie KJ, Kim KI, Peterson LF, Shuai K, Zhang DE, Protein ISGylation modulates the JAK-STAT signaling pathway, Genes & Development, 17, 4, 455–60, February 2003, 12600939, 195994, 10.1101/gad.1056303,
• pupylation, the covalent linkage to the prokaryotic ubiquitin-like protein

Chemical modification of amino acids

• citrullination, or deimination, the conversion of arginine to citrullineJOURNAL, Klareskog L, Rönnelid J, Lundberg K, Padyukov L, Alfredsson L, Immunity to citrullinated proteins in rheumatoid arthritis, Annual Review of Immunology, 26, 651–75, 2008, 18173373, 10.1146/annurev.immunol.26.021607.090244,weblink
• deamidation, the conversion of glutamine to glutamic acid or asparagine to aspartic acid
• eliminylation, the conversion to an alkene by beta-elimination of phosphothreonine and phosphoserine, or dehydration of threonine and serineJOURNAL, Brennan DF, Barford D, Eliminylation: a post-translational modification catalyzed by phosphothreonine lyases, Trends in Biochemical Sciences, 34, 3, 108–14, March 2009, 19233656, 10.1016/j.tibs.2008.11.005,

Structural changes

• disulfide bridges, the covalent linkage of two cysteine amino acids
• lysine-cysteine bridges, the covalent linkage of 1 lysine and 1 or 2 cystine residues via an oxygen atom (NOS and SONOS bridges)JOURNAL, Rabe von Pappenheim, Fabian, Wensien, Marie, Ye, Jin, Uranga, Jon, Irisarri, Iker, de Vries, Jan, Funk, Lisa-Marie, Mata, Ricardo A., Tittmann, Kai, Widespread occurrence of covalent lysine–cysteine redox switches in proteins, Nature Chemical Biology, April 2022, 18, 4, 368–375, 10.1038/s41589-021-00966-5, free, 8964421,
• proteolytic cleavage, cleavage of a protein at a peptide bond
• isoaspartate formation, via the cyclisation of asparagine or aspartic acid amino-acid residues
• racemization
  • of serine by protein-serine epimerase
  • of alanine in dermorphin, a frog opioid peptide
  • of methionine in deltorphin, also a frog opioid peptide
• protein splicing, self-catalytic removal of inteins analogous to mRNA processing

Statistics

Common PTMs by frequency

In 2011, statistics of each post-translational modification experimentally and putatively detected have been compiled using proteome-wide information from the Swiss-Prot database.JOURNAL, Khoury GA, Baliban RC, Floudas CA, Proteome-wide post-translational modification statistics: frequency analysis and curation of the swiss-prot database, Scientific Reports, 1, 90, 90, September 2011, 22034591, 3201773, 10.1038/srep00090, 2011NatSR...1E..90K, The 10 most common experimentally found modifications were as follows:WEB,weblink Proteome-Wide Post-Translational Modification Statistics, selene.princeton.edu, 2011-07-22,weblink" title="web.archive.org/web/20120830234041weblink">weblink 2012-08-30, dead, {| class="wikitable"!Frequency!Modification|58383|Phosphorylation|6751|Acetylation|5526|N-linked glycosylation|2844

#amidation>Amidation

|1619|Hydroxylation|1523|Methylation|1133|O-linked glycosylation|878

Ubiquitin>Ubiquitylation

|826

Pyroglutamic acid>Pyrrolidone carboxylic acid

|504|Sulfation

Common PTMs by residue

Some common post-translational modifications to specific amino-acid residues are shown below. Modifications occur on the side-chain unless indicated otherwise.{| class="wikitable sortable" style="text-align: left" ! Amino Acid !! Abbrev. !! Modification ! Alanine| Ala or A

Acetylation>N-acetylation (N-terminus)

! Arginine| Arg or R

Citrullination>citrulline, methylation

! Asparagine| Asn or N

deamidation to Asp or iso(Asp), N-linked glycosylation, Isopeptide bond>spontaneous isopeptide bond formation

! Aspartic acid| Asp or D

deamidation>isomerization to isoaspartic acid, spontaneous isopeptide bond formation

! Cysteine| Cys or C

disulfide-bond formation, oxidation to sulfenic, sulfinic or sulfonic acid, palmitoylation, Acetylation>N-acetylation (N-terminus), S-nitrosylation

! Glutamine| Gln or Q| cyclization to pyroglutamic acid (N-terminus), deamidation to Glutamic acid or isopeptide bond formation to a lysine by a transglutaminase ! Glutamic acid| Glu or E| cyclization to Pyroglutamic acid (N-terminus), gamma-carboxylation ! Glycine| Gly or G

Myristoylation (N-terminus), Acetylation>N-acetylation (N-terminus)

! Histidine| His or H

Histidine kinase>Phosphorylation

! Isoleucine| Ile or I| ! Leucine| Leu or L| ! Lysine| Lys or K

acetylation, ubiquitylation, SUMO protein>SUMOylation, Protein methylation	, hydroxylation leading to allysine, Isopeptide bond>spontaneous isopeptide bond formation

! Methionine| Met or M

Acetylation>N-acetylation (N-terminus), N-linked Ubiquitination, oxidation to sulfoxide or sulfone

! Phenylalanine| Phe or F| ! Proline| Pro or P| hydroxylation ! Serine| Ser or S

Phosphorylation, O-linked glycosylation, Acetylation>N-acetylation (N-terminus)

! Threonine| Thr or T

Phosphorylation, O-linked glycosylation, Acetylation>N-acetylation (N-terminus)

! Tryptophan| Trp or W| mono- or di-oxidation, formation of kynurenine, tryptophan tryptophylquinone ! Tyrosine| Tyr or Y

Tyrosine sulfation>sulfation, phosphorylation

! Valine| Val or V

Acetylation>N-acetylation (N-terminus)

Databases and tools

(File:Image for Wiki 2.jpg|alt=|thumb|Flowchart of the process and the data sources to predict PTMs.JOURNAL, Lee TY, Huang HD, Hung JH, Huang HY, Yang YS, Wang TH, dbPTM: an information repository of protein post-translational modification, Nucleic Acids Research, 34, Database issue, D622-7, January 2006, 16381945, 1347446, 10.1093/nar/gkj083, |440x440px)Protein sequences contain sequence motifs that are recognized by modifying enzymes, and which can be documented or predicted in PTM databases. With the large number of different modifications being discovered, there is a need to document this sort of information in databases. PTM information can be collected through experimental means or predicted from high-quality, manually curated data. Numerous databases have been created, often with a focus on certain taxonomic groups (e.g. human proteins) or other features.

List of resources

• PhosphoSitePlusJOURNAL, Hornbeck PV, Zhang B, Murray B, Kornhauser JM, Latham V, Skrzypek E, PhosphoSitePlus, 2014: mutations, PTMs and recalibrations, Nucleic Acids Research, 43, Database issue, D512-20, January 2015, 25514926, 4383998, 10.1093/nar/gku1267, – A database of comprehensive information and tools for the study of mammalian protein post-translational modification
• ProteomeScoutJOURNAL, Goel R, Harsha HC, Pandey A, Prasad TS, Human Protein Reference Database and Human Proteinpedia as resources for phosphoproteome analysis, Molecular BioSystems, 8, 2, 453–63, February 2012, 22159132, 3804167, 10.1039/c1mb05340j, – A database of proteins and post-translational modifications experimentally
• Human Protein Reference Database – A database for different modifications and understand different proteins, their class, and function/process related to disease causing proteins
• PROSITEJOURNAL, Sigrist CJ, Cerutti L, de Castro E, Langendijk-Genevaux PS, Bulliard V, Bairoch A, Hulo N, PROSITE, a protein domain database for functional characterization and annotation, Nucleic Acids Research, 38, Database issue, D161-6, January 2010, 19858104, 2808866, 10.1093/nar/gkp885, – A database of Consensus patterns for many types of PTM's including sites
• RESIDJOURNAL, Garavelli JS, The RESID Database of Protein Modifications: 2003 developments, Nucleic Acids Research, 31, 1, 499–501, January 2003, 12520062, 165485, 10.1093/nar/gkg038, – A database consisting of a collection of annotations and structures for PTMs.
• iPTMnet JOURNAL, Huang H, Arighi CN, Ross KE, Ren J, Li G, Chen SC, Wang Q, Cowart J, Vijay-Shanker K, Wu CH, iPTMnet: an integrated resource for protein post-translational modification network discovery, Nucleic Acids Research, 46, 1, D542–D550, January 2018, 2914561, 5753337, 10.1093/nar/gkx1104, – A database that integrates PTM information from several knowledgbases and text mining results.
• dbPTM – A database that shows different PTM's and information regarding their chemical components/structures and a frequency for amino acid modified site
• Uniprot has PTM information although that may be less comprehensive than in more specialized databases.(File:Image for Wiki 1.jpg|alt=|thumb|Effect of PTMs on protein function and physiological processes.JOURNAL, Audagnotto M, Dal Peraro M, In silico prediction tools and molecular modeling, Computational and Structural Biotechnology Journal, 15, 307–319, 2017-03-31, 28458782, 5397102, 10.1016/j.csbj.2017.03.004, |440x440px)
• The O-GlcNAc DatabaseJOURNAL, Wulff-Fuentes E, Berendt RR, Massman L, Danner L, Malard F, Vora J, Kahsay R, Olivier-Van Stichelen S, The human O-GlcNAcome database and meta-analysis, Scientific Data, 8, January 2021, 1, 25, 33479245, 7820439, 10.1038/s41597-021-00810-4, 2021NatSD...8...25W, JOURNAL, Malard F, Wulff-Fuentes E, Berendt RR, Didier G, Olivier-Van Stichelen S, Automatization and self-maintenance of the O-GlcNAcome catalog: a smart scientific database, Database (Oxford), 2021, July 2021, 1, 34279596, 10.1093/database/baab039, 8288053, - A curated database for protein O-GlcNAcylation and referencing more than 14 000 protein entries and 10 000 O-GlcNAc sites.

Tools

List of software for visualization of proteins and their PTMs

• PyMOLJOURNAL, Warnecke A, Sandalova T, Achour A, Harris RA, PyTMs: a useful PyMOL plugin for modeling common post-translational modifications, BMC Bioinformatics, 15, 1, 370, November 2014, 25431162, 4256751, 10.1186/s12859-014-0370-6, free, – introduce a set of common PTM's into protein models
• AWESOMEJOURNAL, Yang Y, Peng X, Ying P, Tian J, Li J, Ke J, Zhu Y, Gong Y, Zou D, Yang N, Wang X, Mei S, Zhong R, Gong J, Chang J, Miao X, AWESOME: a database of SNPs that affect protein post-translational modifications, Nucleic Acids Research, 47, D1, D874–D880, January 2019, 30215764, 6324025, 10.1093/nar/gky821, – Interactive tool to see the role of single nucleotide polymorphisms to PTM's
• ChimeraJOURNAL, Morris JH, Huang CC, Babbitt PC, Ferrin TE, structureViz: linking Cytoscape and UCSF Chimera, Bioinformatics, 23, 17, 2345–7, September 2007, 17623706, 10.1093/bioinformatics/btm329, free, – Interactive Database to visualize molecules

Case examples

{{more citations needed section|date=January 2016}}

• Cleavage and formation of disulfide bridges during the production of insulin
• PTM of histones as regulation of transcription: RNA polymerase control by chromatin structure
• PTM of RNA polymerase II as regulation of transcription
• Cleavage of polypeptide chains as crucial for lectin specificityWEB,weblink 1tp8 - Proteopedia, life in 3D, www.proteopedia.org,

See also

• Protein targeting
• Post-translational regulation

References

{{reflist|30em}}

External links

• weblink" title="web.archive.org/web/20190718064223weblink">dbPTM - database of protein post-translational modifications

(Wayback Machine copy)

• List of posttranslational modifications in ExPASy
• Browse SCOP domains by PTM — from the dcGO database
• weblink" title="web.archive.org/web/20190611022450weblink">Statistics of each post-translational modification from the Swiss-Prot database

(Wayback Machine copy)

• weblink" title="web.archive.org/web/20100619101544weblink">AutoMotif Server - A Computational Protocol for Identification of Post-Translational Modifications in Protein Sequences
• Functional analyses for site-specific phosphorylation of a target protein in cells
• Detection of Post-Translational Modifications after high-accuracy MSMS
• Overview and description of commonly used post-translational modification detection techniques

{{Protein topics}}{{Protein primary structure}}{{Posttranslational modification}}{{Gene expression}}