A protein homodimer is formed by two identical proteins. A protein heterodimer is formed by two different proteins. Most protein dimers in biochemistry are not connected by covalent bonds. An example of a non-covalent heterodimer is the enzyme reverse transcriptase, which is composed of two different amino acid chains.

Why do proteins dimerize?

Not only can dimerization increase the binding affinity for DNA through cooperativity but, by doubling the length of the DNA site bound by the protein, it can also markedly increase binding specificity. Protein oligomerization is particularly important for the assembly of protein complexes involved in gene expression.

How does dimerization occur?

It is a process where two molecules of similar chemical composition come together to form a single polymer known as a dimer. Where does dimerization occur? It happens throughout the cell. ... In the nucleus, hormone receptors, acting as transcription factors, form dimers to increase stability and improve binding to DNA.