What is an ankyrin repeat domain?

Ankyrin repeats typically fold together to form a single, linear solenoid structure called ankyrin repeat domains. These domains are one of the most common protein–protein interaction platforms in nature. They occur in a large number of functionally diverse proteins, mainly from eukaryotes.

What do ankyrin repeats do?

Ankyrin repeat, one of the most widely existing protein motifs in nature, consists of 30-34 amino acid residues and exclusively functions to mediate protein-protein interactions, some of which are directly involved in the development of human cancer and other diseases.

What is the function of glycophorin?

Glycophorin A (GPA) is a sialoglycoprotein that associates with AE1 in erythrocytes forming the Wrb (Wright b) blood group antigen. These two integral proteins may also form a complex during biosynthesis, with GPA facilitating the cell surface expression of AE1.

What is the function of spectrin?

Spectrin is crucial for maintaining the stability and structure of the cell membrane and the shape of a cell. Moreover, it contributes to diverse cell functions such as cell adhesion, cell spreading, and the cell cycle.

Where is Bacteriorhodopsin found?

Bacteriorhodopsin is an integral membrane protein usually found in two-dimensional crystalline patches known as “purple membrane”, which can occupy up to nearly 50% of the surface area of the archaeal cell. The bacteriorhodopsin forms repeating elements that are arranged in chains.

What is glycophorin D?

Glycophorins are heavily glycosylated sialoglycoproteins of human and animal erythrocytes. In humans, there are four glycophorins: A, B, C and D. Glycophorins play an important role in the invasion of red blood cells (RBCs) by malaria parasites, which involves several ligands binding to RBC receptors.

What is spectrin deficiency?

Spectrin deficiency is the most common deficiency found in HS. It is heterogeneous in terms of clinical expression, inheritance (dominant or recessive) and underlying genetic defects (related to alpha- or beta-spectrin gene defects or secondary to ankyrin gene defects).

What is blood spectrin?

Spectrin is the main component of the cell membrane skeleton. It was first identified in erythrocytes, where it forms a filamentous network required for red blood cells to maintain their shape and elasticity (Marchesi and Steers, 1968).

What is ankyrin and spectrin?

Spectrin and ankyrin are membrane skeletal proteins that contribute to mechanical support of plasma membranes and micron-scale organization of diverse membrane-spanning proteins. In contrast, ion channels have continued to evolve ankyrin-binding sites in vertebrates.

Is found in bacteriorhodopsin?

Bacteriorhodopsin is a protein used by Archaea, the most notable one being Halobacteria. Bacteriorhodopsin is an integral membrane protein usually found in two-dimensional crystalline patches known as “purple membrane”, which can occupy up to nearly 50% of the surface area of the archaeal cell.

Why is bacteriorhodopsin purple?

Reprotonation of the retinal molecule by Asp96 restores its original isomerized form. This results in a second proton being released to the EC side. The bacteriorhodopsin molecule is purple and is most efficient at absorbing green light (wavelength 500-650 nm, with the absorption maximum at 568 nm).

What is the function of the repeat in ankyrin?

The repeat has been found in proteins of diverse function such as transcriptional initiators, cell cycle regulators, cytoskeletal, ion transporters, and signal transducers. The ankyrin fold appears to be defined by its structure rather than its function, since there is no specific sequence or structure that is universally recognised by it.

What are the four functional domains of ankyrin?

Structure. Ankyrins contain four functional domains: an N-terminal domain that contains 24 tandem ankyrin repeats, a central domain that binds to spectrin, a death domain that binds to proteins involved in apoptosis, and a C-terminal regulatory domain that is highly variable between different ankyrin proteins.

Where is ankyrin-R found in the body?

In contrast, ankyrin-R is detected only in erythrocytes, striated muscle, and some neurons. 3 In general, an ankyrin protein has four functional domains, a membrane-binding domain (MBD), spectrin-binding domain (SBD), death domain, and a C-terminal regulatory domain ( Figure 23-2 ). Figure 23-2.

Why are non specific interactions important for ankyrin?

These non-specific interactions give ankyrin the property to recognise a large range of proteins as the sequence doesn’t have to be conserved, just the properties of the amino acids. The quasi-independence means that if a binding site is not used, it won’t have a large effect on the overall binding.