X8 protein domain

Last updated
X8
Identifiers
SymbolX8
Pfam PF07983
InterPro IPR012946
SCOP2 1occ / SCOPe / SUPFAM

In molecular biology, the X8 domain, is thought to play a role in targeting the plasmodesmata by providing it with structural support. The domain is able to do this since it contains signal sequences for a glycosylphosphatidylinositol (GPI) linkage to the extracellular face of the plasma membrane. This domain is involved in carbohydrate binding. [1]

Structure

The X8 domain [2] contains 6 conserved cysteine residues that presumably form three disulphide bridges. The domain is also found in an Olive pollen allergen [3] as well as at the C terminus of family 17 glycosyl hydrolases. [4]

Related Research Articles

Glycoside hydrolase

Glycoside hydrolases catalyze the hydrolysis of glycosidic bonds in complex sugars. They are extremely common enzymes with roles in nature including degradation of biomass such as cellulose (cellulase), hemicellulose, and starch (amylase), in anti-bacterial defense strategies, in pathogenesis mechanisms and in normal cellular function. Together with glycosyltransferases, glycosidases form the major catalytic machinery for the synthesis and breakage of glycosidic bonds.

Expansin refers to a family of closely related nonenzymatic proteins found in the plant cell wall, with important roles in plant cell growth, fruit softening, abscission, emergence of root hairs, pollen tube invasion of the stigma and style, meristem function, and other developmental processes where cell wall loosening occurs. Expansins were originally discovered as mediators of acid growth, which refers to the widespread characteristic of growing plant cell walls to expand faster at low (acidic) pH than at neutral pH. Expansins are thus linked to auxin action. They are also linked to cell enlargement and cell wall changes induced by other plant hormones such as gibberellin, cytokinin, ethylene and brassinosteroids.

Ethylene-responsive element binding protein

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Arabinogalactan-proteins (AGPs) are highly glycosylated proteins (glycoproteins) found in the cell walls of plants. Each one consists of a protein with sugar molecules attached. They are members of the wider class of hydroxyproline (Hyp)-rich cell wall glycoproteins, a large and diverse group of glycosylated wall proteins.

CAZy is a database of Carbohydrate-Active enZYmes (CAZymes). The database contains a classification and associated information about enzymes involved in the synthesis, metabolism, and recognition of complex carbohydrates, i.e. disaccharides, oligosaccharides, polysaccharides, and glycoconjugates. Included in the database are families of glycoside hydrolases, glycosyltransferases, polysaccharide lyases, carbohydrate esterases, and non-catalytic carbohydrate-binding modules. The CAZy database also includes a classification of Auxiliary Activity redox enzymes involved in the breakdown of lignocellulose.

Carbohydrate-binding module

In molecular biology, a carbohydrate-binding module (CBM) is a protein domain found in carbohydrate-active enzymes. The majority of these domains have carbohydrate-binding activity. Some of these domains are found on cellulosomal scaffoldin proteins. CBMs were previously known as cellulose-binding domains. CBMs are classified into numerous families, based on amino acid sequence similarity. There are currently 64 families of CBM in the CAZy database.

Glycoside hydrolase family 14

In molecular biology, Glycoside hydrolase family 14 is a family of glycoside hydrolases.

Glycoside hydrolase family 19

In molecular biology, Glycoside hydrolase family 19 is a family of glycoside hydrolases.

Glycoside hydrolase family 2

In molecular biology, Glycoside hydrolase family 2 is a family of glycoside hydrolases.

Glycoside hydrolase family 25

In molecular biology, glycoside hydrolase family 25 is a family of glycoside hydrolases.

Glycoside hydrolase family 28

In molecular biology, glycoside hydrolase family 28 is a family of glycoside hydrolases.

In molecular biology, glycoside hydrolase family 43 is a family of glycoside hydrolases.

Glycoside hydrolase family 45

In molecular biology, glycoside hydrolase family 45 is a family of glycoside hydrolases.

Glycoside hydrolase family 56

In molecular biology, glycoside hydrolase family 56 is a family of glycoside hydrolases.

Glycoside hydrolase family 67

In molecular biology, glycoside hydrolase family 67 is a family of glycoside hydrolases.

In molecular biology, glycoside hydrolase family 70 is a family of glycoside hydrolases.

In molecular biology, glycoside hydrolase family 72 is a family of glycoside hydrolases.

In molecular biology, glycoside hydrolase family 79 is a family of glycoside hydrolases.

In molecular biology, glycoside hydrolase family 97 is a family of glycoside hydrolases.

Glycoside hydrolase family 22 Family of glycoside hydrolases

In molecular biology, glycoside hydrolase family 22 is a family of glycoside hydrolases.

References

  1. Simpson C, Thomas C, Findlay K, Bayer E, Maule AJ (2009). "An Arabidopsis GPI-anchor plasmodesmal neck protein with callose binding activity and potential to regulate cell-to-cell trafficking". Plant Cell. 21 (2): 581–94. doi:10.1105/tpc.108.060145. PMC   2660613 . PMID   19223515.
  2. Henrissat B, Davies GJ (December 2000). "Glycoside hydrolases and glycosyltransferases. Families, modules, and implications for genomics". Plant Physiol. 124 (4): 1515–9. doi:10.1104/pp.124.4.1515. PMC   1539306 . PMID   11115868.
  3. Barral P, Batanero E, Palomares O, Quiralte J, Villalba M, RodrÃguez R (March 2004). "A major allergen from pollen defines a novel family of plant proteins and shows intra- and interspecies [correction of interspecie] cross-reactivity". J. Immunol. 172 (6): 3644–51. doi: 10.4049/jimmunol.172.6.3644 . PMID   15004167.
  4. Henrissat B, Coutinho PM, Davies GJ (September 2001). "A census of carbohydrate-active enzymes in the genome of Arabidopsis thaliana". Plant Mol. Biol. 47 (1–2): 55–72. doi:10.1007/978-94-010-0668-2_4. ISBN   978-94-010-3861-4. PMID   11554480.
This article incorporates text from the public domain Pfam and InterPro: IPR012946