Spectrin repeats are found in several proteins involved in cytoskeletal structure. These include

spectrin Spectrin is a cytoskeletal protein that lines the intracellular side of the plasma membrane in eukaryotic cells. Spectrin forms pentagonal or hexagonal arrangements, forming a scaffold and playing an important role in maintenance of plasma mem ...

, alpha-

actinin Actinin is a microfilament protein. The functional protein is an anti-parallel dimer, which cross-links the thin filaments in adjacent sarcomeres, and therefore coordinates contractions between sarcomeres in the horizontal axis. Alpha-actinin is ...

dystrophin Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costa ...

and more recently the plakin family. The spectrin repeat forms a three-

helix bundle A helix bundle is a small protein fold composed of several alpha helices that are usually nearly parallel or antiparallel to each other. Three-helix bundles Three-helix bundles are among the smallest and fastest known cooperatively folding struct ...

. These conform to the rules of the

heptad repeat The heptad repeat is an example of a structural motif that consists of a repeating pattern of seven amino acids: ''a b c d e f g'' H P P H C P C where H represents hydrophobic residues, C represents, typically, charged residues, and P repre ...

. Spectrin repeats give rise to linear proteins. This however may be due to sample bias in which linear and rigid structures are more amenable to crystallization. There are hints however, that some proteins harbouring spectrin repeats may also be flexible. This is most likely due to specifically evolved functional purposes.

Human proteins containing this domain

ACTN1 Alpha-actinin-1 is a protein that in humans is encoded by the ''ACTN1'' gene. Function Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeleton, cytoskeletal proteins, including the alpha and bet ...

; ACTN2;

ACTN3 Alpha-actinin-3, also known as alpha-actinin skeletal muscle isoform 3 or F-actin cross-linking protein, is a protein that in humans is encoded by the ''ACTN3'' gene (named sprinter gene, speed gene or athlete gene) located on chromosome 11. All ...

; ACTN4; AKAP6; SYNE3; CATX-15; DMD; DRP2; DST; KALRN; MACF1; MCF2L; SPTA1;

SPTAN1 Alpha II-spectrin, also known as Spectrin alpha chain, brain is a protein that in humans is encoded by the ''SPTAN1'' gene. Alpha II-spectrin is expressed in a variety of tissues, and is highly expressed in cardiac muscle at sarcomere, Z-disc str ...

; SPTB; SPTBN1;

SPTBN2 Spectrin beta chain, brain 2 is a protein that in humans is encoded by the ''SPTBN2'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA th ...

; SPTBN4; SPTBN5; SYNE1;

SYNE2 Nesprin-2 is a protein that in humans is encoded by the ''SYNE2'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed t ...

; TRIO; UTRN;

References

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Human proteins containing this domain

References

Further reading