The reason that many proteins adopt a particular oligomeric form is far from obvious. In this chapter, we discuss potential advantages of proteins self‑assembling into specific quaternary structures. A number of case studies are presented in which wild‑type proteins have been mutated to...

Protein‑protein associations represent the building blocks of biological systems. The classification of different types of protein association is fundamental to an understanding of the interactions they exhibit. A protein association can be classified as homo‑ (identical components) or...

Controlled cell death, or apoptosis, occurs in response to many different environmental stimuli. The apoptotic cascade that occurs within the cell in response to these cues leads to morphological and biochemical changes that trigger the dismantling and packaging of the cell. Caspases are a...

Three‑dimensional domain swapping is the process by which two identical protein chains exchange a part of their structure to form an intertwined dimer or higher‑order oligomer. The phenomenon has been observed in the crystal structures of a range of different proteins. In this chapter we...

In this chapter we review recent studies of repeat proteins, a class of proteins consisting of tandem arrays of small structural motifs that stack approximately linearly to produce elongated structures. We discuss the observation that, despite lacking the long‑range tertiary interactions...

Eukaryotic transcription factors bind DNA and typically serve to localize large multiprotein complexes to particular genes to up‑ or downregulate transcription, thereby coordinating cellular responses to a variety of signals. Different combinations of transcription factors within...

Protein dimers and multimers are often employed by nature for DNA and RNA handling and formation of specific, high‑affinity protein‑oligonucleotide complexes. The repeating structure of dsDNA lends itself to recognition by multimeric protein complexes that can assemble about the helical...

There are many different techniques available to biologists and biochemists that can be used to detect and characterize the self‑association of proteins. Each technique has strengths and weaknesses and it is often useful to combine several approaches to  maximize the former and minimize the...

Cell membranes present a naturally impervious barrier to aqueous solutes, such that the physiochemical environment on either side of the lipid bilayer can substantially differ. Integral membrane proteins are embedded in this heterogeneous lipid environment, wherein the juxtaposition of apolar...

The specific self‑association of proteins to form homodimers and higher order oligomers is an extremely common event in biological systems. In this chapter we review the prevalence of protein oligomerization and discuss the likely origins of this phenomenon. We also outline many of the...