Beta-sandwich, β-sandwich domains consisting of 80 to 350 amino acids occur commonly in
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
. They are characterized by two opposing antiparallel
beta sheet
The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a g ...
s (β-sheets).
The number of strands found in such domains may differ from one protein to another. β-sandwich domains are subdivided in a variety of different folds. The
immunoglobulin-type fold found in
antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
(Ig-fold) consists of a sandwich arrangement of 7 and 9 antiparallel
β-strand
The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a g ...
s arranged in two
β-sheets
The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a gen ...
with a
Greek-key topology.
The Greek-key topology is also found in
Human Transthyretin. The
jelly-roll topology is found in carbohydrate binding proteins such as
concanavalin A and various
lectins, in the
collagen
Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole ...
binding domain of ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive ...
''
Adhesin and in modules that bind
fibronectin as found in
Tenascin (Third Fibronectin Type III Repeat). The
L-type lectin domain
In molecular biology the L-like lectin domain is a protein domain found in lectins which are similar to the leguminous plant lectins.
Lectins are structurally diverse proteins that bind to specific carbohydrates. This family includes the VIP36 ...
is a variation of the jelly roll fold. The
C2 domain in its typical version (PKC-C2) is a β-sandwich composed of 8
beta-strand
The beta sheet, (β-sheet) (also β-pleated sheet) is a common structural motif, motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone chain, backb ...
s (β-strands).
References
{{Protein-stub
Protein structural motifs