18-strand β barrel. Bacterial sucrose-specific porin from S. typhimurium. It sits in a membrane and allows sucrose to diffuse through. (PDB: 1A0S)
8-strand β barrel. Human retinol-binding protein bound to retinol (vitamin A) in blue. (PDB: 1RBP)
In protein structures, a beta barrel(β barrel) is a beta sheet (β sheet) composed of tandem repeats that twists and coils to form a closed toroidal structure in which the first strand is bonded to the last strand (hydrogen bond). Beta-strands in many beta-barrels are arranged in an antiparallel fashion. Beta barrel structures are named for resemblance to the barrels used to contain liquids. Most of them are water-soluble outer membrane proteins and frequently bind hydrophobic ligands in the barrel center, as in lipocalins. Others span cell membranes and are commonly found in porins. Porin-like barrel structures are encoded by as many as 2–3% of the genes in Gram-negative bacteria.[1] It has been shown that more than 600 proteins with various function such as oxidase, dismutase, and amylase contain the beta barrel structure.[2]
In many cases, the strands contain alternating polar and non-polar (hydrophilic and hydrophobic) amino acids, so that the hydrophobic residues are oriented into the interior of the barrel to form a hydrophobic core and the polar residues are oriented toward the outside of the barrel on the solvent-exposed surface. Porins and other membrane proteins containing beta barrels reverse this pattern, with hydrophobic residues oriented toward the exterior where they contact the surrounding lipids, and hydrophilic residues oriented toward the aqueous interior pore.
All beta-barrels can be classified in terms of two integer parameters: the number of strands in the beta-sheet, n, and the "shear number", S, a measure of the stagger of the strands in the beta-sheet.[3] These two parameters (n and S) are related to the inclination angle of the beta strands relative to the axis of the barrel.[4][5][6]
^Wimley WC (August 2003). "The versatile beta-barrel membrane protein". Current Opinion in Structural Biology. 13 (4): 404–411. doi:10.1016/S0959-440X(03)00099-X. PMID 12948769.
^Lu Y, Yeung N, Sieracki N, Marshall NM (August 2009). "Design of functional metalloproteins". Nature. 460 (7257): 855–862. Bibcode:2009Natur.460..855L. doi:10.1038/nature08304. PMC 2770889. PMID 19675646.
^Murzin AG, Lesk AM, Chothia C (March 1994). "Principles determining the structure of beta-sheet barrels in proteins. I. A theoretical analysis". Journal of Molecular Biology. 236 (5): 1369–1381. doi:10.1016/0022-2836(94)90064-7. PMID 8126726.
^Murzin AG, Lesk AM, Chothia C (March 1994). "Principles determining the structure of beta-sheet barrels in proteins. II. The observed structures". Journal of Molecular Biology. 236 (5): 1382–1400. doi:10.1016/0022-2836(94)90065-5. PMID 8126727.
^Liu WM (January 1998). "Shear numbers of protein beta-barrels: definition refinements and statistics". Journal of Molecular Biology. 275 (4): 541–545. doi:10.1006/jmbi.1997.1501. PMID 9466929.
^Hayward S, Milner-White EJ (October 2017). "Geometrical principles of homomeric β-barrels and β-helices: Application to modeling amyloid protofilaments" (PDF). Proteins. 85 (10): 1866–1881. doi:10.1002/prot.25341. PMID 28646497. S2CID 206410314.
In protein structures, a betabarrel (β barrel) is a beta sheet (β sheet) composed of tandem repeats that twists and coils to form a closed toroidal structure...
An alpha/betabarrel is a protein fold formed by units composed of a short α-helix followed by two anti-parallel β-strands, followed by an α-helix and...
detergents or nonpolar solvents for extraction, although some of them (beta-barrels) can be also extracted using denaturing agents. The peptide sequence...
The TIM barrel (triose-phosphate isomerase), also known as an alpha/betabarrel,: 252 is a conserved protein fold consisting of eight alpha helices (α-helices)...
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)...
(Y66H),Y145F for higher quantum yield, H148G for creating a hole into the beta-barrel and several other mutations that increase solubility. Zn(II) binding...
11-stranded betabarrel. This structure is almost identical to the tertiary structure of DsRed which also has an 11-stranded betabarrel, and is similar...
first identified member of the pore forming beta-barrel toxin family. This toxin consists mostly of beta-sheets (68%) with only about 10% alpha-helices...
roll (options), an options trading strategy Jelly roll fold, a type of betabarrel protein domain structure Jelly roll (battery), a type of battery construction...
metabolites between the cytosol and the intermembrane space. It is formed as a betabarrel that spans the outer membrane, similar to that in the gram-negative bacterial...
channel is composed of a 12-stranded beta-barrel that spans the outer membrane, and a long tail helical barrel that spans the periplasm. Examples include...
elaboration on the Greek key motif and is sometimes considered a form of betabarrel. It is very common in viral proteins, particularly viral capsid proteins...
membrane. Proteins which use this pathway have the capability to form a beta-barrel with their C-terminus which inserts into the outer membrane, allowing...
hand" fold (InterPro: IPR043502) and the "double psi betabarrel" (often simply "double-barrel") fold. The former is seen in almost all DNA polymerases...
translocates inside the beta-barrel, leading to transportation of the passenger domain from the C terminus to the N terminus through the beta-barrel lumen. In essence...
prediction is the homology (PolyPhobius).” It is also possible to predict beta-barrel membrane proteins' topology. Endomembrane system Integral membrane protein...
communications protocol Translocon at the outer membrane of chloroplast, in betabarrel Total organic carbon in an organic compound TOC1 (gene), a gene that...
assembly of betabarrel proteins, this includes proteins such as the Tom40 import pore and porin. Like all mitochondrial proteins, betabarrel proteins are...
3-layered beta-sandwiches fold and a core, 6-stranded beta-barrel structure. The beta-barrel has a hydrophobic core. The triple-layered beta-sandwich is...
monomer contains a core beta-barrel structure called the jelly roll motif of eight strands arranged in two adjacent antiparallel beta sheets, labeled CHEF...
from 86 to 100 kDa and is composed of a membrane-spanning 24-stranded betabarrel domain, reminiscent of porins, and of four periplasmic soluble domains:...
Global Information
