# Protein dimer

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Protein_dimer
> Markdown URL: https://mediated.wiki/source/Protein_dimer.md
> Source: https://en.wikipedia.org/wiki/Protein_dimer
> Source revision: 1341248881
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Macromolecular complex formed by two, usually non-covalently bound, macromolecules

[Ribbon diagram](/source/Ribbon_diagram) of a dimer of *[Escherichia coli](/source/Escherichia_coli)* [galactose-1-phosphate uridylyltransferase](/source/Galactose-1-phosphate_uridylyltransferase) (GALT) in complex with [UDP-galactose](/source/UDP-galactose). Potassium, zinc, and iron ions are visible as purple, gray, and bronze-colored spheres respectively.

In [biochemistry](/source/Biochemistry), a **protein dimer** is a [macromolecular](/source/Macromolecular) complex or [multimer](/source/Protein_multimer) formed by two [protein](/source/Protein) [monomers](/source/Monomer#Biopolymers), or single proteins, which are usually [non-covalently bound](/source/Non-covalent_interaction). Many macromolecules, such as proteins or [nucleic acids](/source/Nucleic_acid), form [dimers](/source/Dimer_(chemistry)). The word *dimer* has roots meaning "two parts", *[di-](https://en.wiktionary.org/wiki/di-#Prefix)* + *[-mer](https://en.wiktionary.org/wiki/-mer#Suffix)*. A protein dimer is a type of [protein quaternary structure](/source/Protein_quaternary_structure).

A protein **homodimer** is formed by two identical [proteins](/source/Protein) while a protein **heterodimer** is formed by two different proteins.

Most protein dimers in biochemistry are not connected by [covalent bonds](/source/Covalent_bond). An example of a non-covalent heterodimer is the enzyme [reverse transcriptase](/source/Reverse_transcriptase), which is composed of two different [amino acid](/source/Amino_acid) chains.[1] An exception is dimers that are linked by [disulfide bridges](/source/Disulfide_bridge) such as the homodimeric protein [NEMO](/source/IKBKG).[2]

Some proteins contain specialized domains to ensure dimerization (dimerization domains) and specificity.[3]

The [G protein-coupled](/source/G_protein-coupled_receptor) [cannabinoid receptors](/source/Cannabinoid_receptor) have the ability to form both homo- and heterodimers with several types of receptors such as [mu-opioid](/source/%CE%9C-opioid_receptor), [dopamine](/source/Dopamine_receptor) and [adenosine A2](/source/Adenosine_A2A_receptor) receptors.[4]

## Examples

- [Transcription factors](/source/Transcription_factor) - [Leucine zipper](/source/Leucine_zipper) motif proteins

- [14-3-3 proteins](/source/14-3-3_protein)

- [Variable surface glycoproteins](/source/Variable_surface_glycoprotein) of the *Trypanosoma* parasite

- [Tubulin](/source/Tubulin)

- Some [clotting factors](/source/Clotting_factors) - [Factor XI](/source/Factor_XI) - [Factor XIII](/source/Factor_XIII) - [Fibrinogen](/source/Fibrin)

- Some [receptors](/source/Receptor_(biochemistry)) - [Nuclear receptors](/source/Nuclear_receptor) - [G protein](/source/G_protein) βγ-subunit dimer - [Toll-like receptor](/source/Toll-like_receptor) - [Receptor tyrosine kinases](/source/Receptor_tyrosine_kinase)

- Some [enzymes](/source/Enzymes) - [Type II restriction enzymes](/source/Restriction_enzyme#Type_II) - [Triosephosphateisomerase](/source/Triosephosphateisomerase) (TIM) - [Alcohol dehydrogenase](/source/Alcohol_dehydrogenase)

- Some viral proteins - [Mammarenaviruses](/source/Arenavirus) Z matrix protein [5][6][7][8]

## Alkaline phosphatase

*E. coli* [alkaline phosphatase](/source/Alkaline_phosphatase), a dimer enzyme, exhibits [intragenic complementation](/source/Complementation_(genetics)).[9] That is, when particular [mutant](/source/Mutant) versions of alkaline phosphatase were combined, the heterodimeric enzymes formed as a result exhibited a higher level of activity than would be expected based on the relative activities of the parental enzymes. These findings indicated that the dimer structure of the *E. coli* alkaline phosphatase allows cooperative interactions between the constituent mutant monomers that can generate a more functional form of the [holoenzyme](/source/Holoenzyme). The dimer has two active sites, each containing two zinc ions and a magnesium ion.[10]

## See also

- [Dimerization](/source/Dimerization)

- [Protein trimer](/source/Protein_trimer)

- [Oligomer](/source/Oligomer)

- [ProtCID](/source/ProtCID)

## References

1. **[^](#cite_ref-pmid16884295_1-0)** Sluis-Cremer N, Hamamouch N, San Félix A, Velazquez S, Balzarini J, Camarasa MJ (August 2006). "Structure-activity relationships of [2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]- 3'-spiro-5' '-(4' '-amino-1' ',2' '-oxathiole-2' ',2' '-dioxide)thymine derivatives as inhibitors of HIV-1 reverse transcriptase dimerization". *J. Med. Chem*. **49** (16): 4834–41. [doi](/source/Doi_(identifier)):[10.1021/jm0604575](https://doi.org/10.1021%2Fjm0604575). [PMID](/source/PMID_(identifier)) [16884295](https://pubmed.ncbi.nlm.nih.gov/16884295).

1. **[^](#cite_ref-pmid18164680_2-0)** Herscovitch M, Comb W, Ennis T, Coleman K, Yong S, Armstead B, Kalaitzidis D, Chandani S, Gilmore TD (February 2008). ["Intermolecular disulfide bond formation in the NEMO dimer requires Cys54 and Cys347"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2277332). *Biochemical and Biophysical Research Communications*. **367** (1): 103–8. [doi](/source/Doi_(identifier)):[10.1016/j.bbrc.2007.12.123](https://doi.org/10.1016%2Fj.bbrc.2007.12.123). [PMC](/source/PMC_(identifier)) [2277332](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2277332). [PMID](/source/PMID_(identifier)) [18164680](https://pubmed.ncbi.nlm.nih.gov/18164680).

1. **[^](#cite_ref-3)** Amoutzias, Grigoris D.; Robertson, David L.; Van de Peer, Yves; Oliver, Stephen G. (2008-05-01). "Choose your partners: dimerization in eukaryotic transcription factors". *Trends in Biochemical Sciences*. **33** (5): 220–229. [doi](/source/Doi_(identifier)):[10.1016/j.tibs.2008.02.002](https://doi.org/10.1016%2Fj.tibs.2008.02.002). [ISSN](/source/ISSN_(identifier)) [0968-0004](https://search.worldcat.org/issn/0968-0004). [PMID](/source/PMID_(identifier)) [18406148](https://pubmed.ncbi.nlm.nih.gov/18406148).

1. **[^](#cite_ref-4)** Filipiuc, Leontina Elena; Ababei, Daniela Carmen; Alexa-Stratulat, Teodora; Pricope, Cosmin Vasilica; Bild, Veronica; Stefanescu, Raluca; Stanciu, Gabriela Dumitrita; Tamba, Bogdan-Ionel (2021-11-01). ["Major Phytocannabinoids and Their Related Compounds: Should We Only Search for Drugs That Act on Cannabinoid Receptors?"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8625816). *Pharmaceutics*. **13** (11): 1823. [doi](/source/Doi_(identifier)):[10.3390/pharmaceutics13111823](https://doi.org/10.3390%2Fpharmaceutics13111823). [ISSN](/source/ISSN_(identifier)) [1999-4923](https://search.worldcat.org/issn/1999-4923). [PMC](/source/PMC_(identifier)) [8625816](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8625816). [PMID](/source/PMID_(identifier)) [34834237](https://pubmed.ncbi.nlm.nih.gov/34834237).

1. **[^](#cite_ref-5)** Witwit, Haydar; de la Torre, Juan C. (2025-04-29). ["Mammarenavirus Z Protein Myristoylation and Oligomerization Are Not Required for Its Dose-Dependent Inhibitory Effect on vRNP Activity"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12163724). *BioChem*. **5** (2): 10. [doi](/source/Doi_(identifier)):[10.3390/biochem5020010](https://doi.org/10.3390%2Fbiochem5020010). [ISSN](/source/ISSN_(identifier)) [2673-6411](https://search.worldcat.org/issn/2673-6411). [PMC](/source/PMC_(identifier)) [12163724](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12163724).

1. **[^](#cite_ref-6)** Witwit, Haydar; Ibanez, Pablo; Zhou, Ruifeng; Jackson, Nathaniel; Escobedo, Ruby; Cubitt, Beatrice; Khafaji, Roaa; Sattler, Rachel Y.; Martinez-Sobrido, Luis; de la Torre, Juan Carlos (2026-02-04). ["Prolyl tRNA Synthetase Is Required for Mammarenavirus Multiplication"](https://www.mdpi.com/1999-4915/18/2/202). *Viruses*. **18** (2): 202. [doi](/source/Doi_(identifier)):[10.3390/v18020202](https://doi.org/10.3390%2Fv18020202). [ISSN](/source/ISSN_(identifier)) [1999-4915](https://search.worldcat.org/issn/1999-4915).

1. **[^](#cite_ref-7)** Witwit, Haydar; Betancourt, Carlos Alberto; Cubitt, Beatrice; Khafaji, Roaa; Kowalski, Heinrich; Jackson, Nathaniel; Ye, Chengjin; Martinez-Sobrido, Luis; de la Torre, Juan C. (2024-08-26). ["Cellular N-Myristoyl Transferases Are Required for Mammarenavirus Multiplication"](https://www.mdpi.com/1999-4915/16/9/1362). *Viruses*. **16** (9): 1362. [doi](/source/Doi_(identifier)):[10.3390/v16091362](https://doi.org/10.3390%2Fv16091362). [ISSN](/source/ISSN_(identifier)) [1999-4915](https://search.worldcat.org/issn/1999-4915). [PMC](/source/PMC_(identifier)) [11436053](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11436053). [PMID](/source/PMID_(identifier)) [39339839](https://pubmed.ncbi.nlm.nih.gov/39339839).

1. **[^](#cite_ref-8)** Witwit, Haydar; de la Torre, Juan C. (2025-10-01). ["N-myristoyltransferase inhibitors as candidate broad-spectrum antivirals to treat viral infections promoted by immunosuppression associated with JAK inhibitors therapy"](https://www.sciencedirect.com/science/article/pii/S0166354225001846). *Antiviral Research*. **242** 106258. [doi](/source/Doi_(identifier)):[10.1016/j.antiviral.2025.106258](https://doi.org/10.1016%2Fj.antiviral.2025.106258). [ISSN](/source/ISSN_(identifier)) [0166-3542](https://search.worldcat.org/issn/0166-3542).

1. **[^](#cite_ref-9)** Hehir, Michael J.; Murphy, Jennifer E.; Kantrowitz, Evan R. (2000). "Characterization of Heterodimeric Alkaline Phosphatases from Escherichia coli: An Investigation of Intragenic Complementation". *Journal of Molecular Biology*. **304** (4): 645–656. [doi](/source/Doi_(identifier)):[10.1006/jmbi.2000.4230](https://doi.org/10.1006%2Fjmbi.2000.4230). [PMID](/source/PMID_(identifier)) [11099386](https://pubmed.ncbi.nlm.nih.gov/11099386).

1. **[^](#cite_ref-10)** Hjorleifsson, Jens Gu[eth]Mundur, and Bjarni Asgeirsson. "Cold-Active Alkaline Phosphatase Is Irreversibly Transformed into an Inactive Dimer by Low Urea Concentrations." *Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics*, vol. 1864, no. 7, 2016, pp. 755–765, [https://doi.org/10.1016/j.bbapap.2016.03.016](https://doi.org/10.1016/j.bbapap.2016.03.016).

- Conn. (2013). *G protein coupled receptors modeling, activation, interactions and virtual screening* (1st ed.). Academic Press.

- Matthews, Jacqueline M. *Protein Dimerization and Oligomerization in Biology*. Springer New York, 2012.

[Portal](https://en.wikipedia.org/wiki/Wikipedia:Contents/Portals):
- [Biology](https://en.wikipedia.org/wiki/Portal:Biology)

---
Adapted from the Wikipedia article [Protein dimer](https://en.wikipedia.org/wiki/Protein_dimer) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Protein_dimer?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.