A ternary complex is a protein complex containing three different molecules that are bound together. In structural biology, ternary complex can also be used to describe a crystal containing a protein with two small molecules bound, such as a cofactor and a substrate; or a complex formed between two proteins and a single substrate. In Immunology, ternary complex can refer to the MHC–peptide–T-cell-receptor complex formed when T cells recognize epitopes of an antigen. Another important example is the ternary complex formed during eukaryotic translation, in which ternary complex composed of eIF2 + GTP + Met-tRNAiMet is formed. A ternary complex can be a complex formed between two substrate molecules and an enzyme. This is seen in multi-substrate enzyme-catalyzed reactions where two substrates and two products can be formed. The ternary complex is an intermediate species in this type of enzyme-catalyzed reaction. An example for a ternary complex is seen in the random-order mechanism or the compulsory-order mechanism of enzyme catalysis for multiple substrates.
The term ternary complex can also refer to a polymer formed by electrostatic interactions.
Trevor Palmer (Enzymes, 2nd edition)
References
Clar, Steven G.; Tamanoi, Fuyuhiko (2006). Protein methyltransferass. Academic Press. pp. 162–172. ISBN 978-0-12-122725-8. 978-0-12-122725-8 ↩
Robert, Francis; Kapp, Lee D.; Khan, Shakila N.; Acker, Michael G.; Kolitz, Sarah; Kazemi, Shirin; Kaufman, Randal J.; Merrick, William C.; Koromilas, Antonis E.; Lorsch, Jon R.; Pelletier, Jerry (November 2006). Schmid, Sandra (ed.). "Initiation of Protein Synthesis by Hepatitis C Virus Is Refractory to Reduced eIF2 · GTP · Met-tRNA i Met Ternary Complex Availability". Molecular Biology of the Cell. 17 (11): 4632–4644. doi:10.1091/mbc.e06-06-0478. ISSN 1059-1524. PMC 1635388. PMID 16928960. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1635388 ↩
Hindson, V. John; Shaw, William V. (2003-03-01). "Random-Order Ternary Complex Reaction Mechanism of Serine Acetyltransferase from Escherichia coli". Biochemistry. 42 (10): 3113–3119. doi:10.1021/bi0267893. ISSN 0006-2960. PMID 12627979. https://pubs.acs.org/doi/10.1021/bi0267893 ↩
Cabuil, Valérie; Levitz, Pierre; Treiner, Clande (2004). Trends in colloid and interface science XVII. Springer. p. 45. ISBN 978-3-540-20073-4. 978-3-540-20073-4 ↩